Audio setup old
Specific notes on my Linux audio workflow. See also Soundbox.
What do I like to do?
- All controller and keyboard, no mouse interaction
- Headphone click track and visual metronome
- Live recording and looping of MIDI note patterns
- Live recording and looping of MIDI control patterns
- Generation of MIDI note and control patterns
- Dynamic routing of MIDI note and control messages
- MIDI automation/apreggiation
- MIDI velocity scaling
- MIDI gating
- MIDI swing/groove
- MIDI delay/loop
- MIDI key transpose
- MIDI scale alteration/filtering
- MIDI chord generation
- Soundfonts and sample bank synthesis
- Drum, bass, pad and lead synthesis
- Audio FX - gating, reverb, delay, distortion, filters, etc.
- Synchronised audio loop capture and loop FX
- Have a system that is expressive enough for both live and studio use
- Have a system that is quick to navigate and configure a workflow in
- Have a system with robust session management
- Ideally touching no Win VST
MIDI control hardware
- Yamaha DJX
- Korg Nanokontrol 2
- Numark DJ2GO
- MIDI to USB adapter for DJX
- QWERTY keyboard to MIDI via midikb
Audio setup
- Audio systems
- ALSA
- PulseAudio - sending PA app outputs to jack sinks
- JACK - jackd 2, multiprocessor, D-Bus enabled
- Cadence - good JACK configuration utility, automatic ALSA/PulseAudio/MIDI bridging
cadence # JACK config and start/stop non-session-manager -- --session-root ~/audio/NSM # same session root directory for all projects # alias the command "nsm" for this, starting in a terminal for output/error messages
Session management
- Non Session Manager
- buggy but works.
- JACKPatch - NSM tool to save JACK patch connections - known to loose configuration when programs crash
jackpatch # nsm specific util to save and restore jack connections # can occasionally bugs out and lose settings on some systems
From the commandline, in the project directory
aj-snapshot projectname.aj.bak # backup JACK connection snapshot as JACKPatch can lose its memory on a bad crash or accidental NSM entry removal
- Carla
- Can start/stop JACK engine
- Provisional JACK app launcher - buggy, not enough ports can be exposed.
- Catia
Hosts and routing
- Carla - plugin host and graph patcher
- LV2, LASDSPA, DSSI, Linux/Win VST
- plugin tempo sync
- internal/external Patchbay - buggyish views, no grid
- MIDI automation CC per parameter but no MIDI learn
- no channel strips
- Patchage - JACK/ALSA patchbay - same graph engine as Ingen
- Looks better than Catia, though Carla has an internal rack patchbay view
- Ingen - modular host with internal units and inline LV2 plugins, MIDI learn
- no channel strips
- needs webkitgtk, which doesn't have an Arch binary package and takes more than a day to build
- Qtractor - plugin host and channel routing
- SDI interface is hard to work with
- Ardour - plugin host and channel routing
- very good channels/routing
- no tempo change on JACK Transport tempo change
- Non Mixer - modular mixer with MIDI2OSC learn
- LV2 hosting with falktx fork
- mixer format so automatic channel strips
- interface is slow to work with
- alsa_in/alsa_out - for adding to JACK additional input and output devices beyond the primary sound device
carla # plugin host nsm-proxy patchage -A # GUI patch graph manager, less frustrating than that of Carla # via nsm-proxy for the -A argument to not load ALSA # Ctrl-g to sort, Ctrl-f to fit-to-screen zoom ( nsm-proxy nsm-ingen # via nsm-proxy, hack of sequencer64 script above, copies in a blank project, starts ingen modular host engine and gui # ingen -eg project.ingen ) ( nsm-proxy alsa_out -j "USB Out 1" -d hw:5 -q 1 2>&1 1> /dev/null & nsm-proxy alsa_out -j "USB Out 2" -d hw:6 -q 1 2>&1 1> /dev/null & # additional 2 stereo outputs, USB soundcards for DJ main and headphone )
Click track / visual metronome
- Click track options
- Represented by a percussion part channel, or
- Bleep - synth, seq64
- Visual metronome
- JVMetro - visual
- something else for extended section length
Workflow
Summary:
- Programming, live recording and generation of MIDI note and control sequences
- Channelised part patterns control
- Easy switching of note and control routing
- Easy switching between modes of synthesis using Program Changes and routing
Details:
- MIDI controlled MIDI routing/switching using mididings scenes (or Mooney.lv2 / Pure Data)
- momentary and latched control flow
- recording and looping of control flow
mididings scenes:
- 1 - nano control of seq64 horizontal column level selection
- 2 - channel strip' control of parts using subscenes
MIDI channels to song part mapping:
- kick
- kick2
- snare
- hihat
- cymbal
- perc1
- perc2
- perc3
- bass1
- bass2
- pad1
- pad2
- lead1
- lead2
- lead3
- seq64 control
control pattern insert/send patches:
- notes - delay, sustenuto, arpeggiation, swing/groove, transpose, alteration/filtering, chording generation/splitting
- control messages - patterns & LFOs - volume level / gate, modulation, pitchbend, detune, etc.
routing patch destinations:
- for percussion - ALVDrums, DrMr, Stegosaurus, DrumSynth, soundfonts, etc.
- for synths - ZynAddSubFX, etc.
problems with control patterns:
- when a pattern is disabled, the last sent value, which could be 'off'
MIDI routing
See also Audio#MIDI routing
Software:
- a2jmidid - via Cadence, as jackd 2 doesn't do the Metadata API yet so hardware interface names are opaque.
- jack_midi_dump - MIDI monitor, prints to terminal stdout.
- vmpk - virtual keyboard with CC send
nsm-proxy a2jmidid -eu # because cadence misses -u arg nsm-proxy xterm -e jack_midi_dump # MIDI monitoring
MIDI processing
See also Audio#MIDI processing GUI
General processing:
- mididings - filtering, scripting, switching via 'scenes' and MIDI program change messages. mididings.py
nsm-proxy mididings -f path/to/m_control.py # nsm-proxy livedings -l 56801 -p 56800 -T -f "Sans 22 bold" -F "Sans 22 bold" -w 50 -n "control" nsm-proxy mididings -f path/to/m_drums.py # drum selection. to redo. nsm-proxy livedings -T -f "Sans 22 bold" -F "Sans 22 bold"
Notes:
- pizmidi: midiStuckNoteKiller
- pizmidi: midiInvertNotes
- pizmidi: midiAlias - Note values are reflected between a "Nyquist Note" and a "Zero Note," similar to the effect of audio sample aliasing.
Channel:
- pizmidi: midiChannelize - Transforms everything to the selected channel. When set to "No Change" the plugin will have no effect.
- pizmidi: midiChannelFilter - Only passes through data on the selected channel.
Program Change (PC):
- pizmidi: midiProgramChange - can be sent to mididings for scene changes
- pizmidi: midiMultiProgramChange - Uses input program change to trigger selected program changes on all channels.
CC processing
CC processing:
- pizmidi: midiNotchFilter - Isolate, remove, or channelize up to 4 specific midi messages.
- pizmidi: midiCCStepper - Quantize CC events by value or in time.
- midifilter.lv2: ScaleCC - scale CC range sent to delay down for easier time sync length selection
CC routing:
- pizmidi: midi16CCRouter - Changes up to 16 CCs to 16 other CCs. Optionally responds to Program Change.
CC conversion:
- pizmidi: midiConverter3 - Change and convert between CC, Channel Pressure, Poly Aftertouch, Program Change, Pitch Bend, NRPN/RPN, Note On/Off, and other messages in various ways. Pitch Bend and (N)RPN conversions will use the full 14-bit values when possible.
- midifilter.lv2: Note2CC
- pizmidi: midiNRPNConverter - Converts between NRPN/RPN and CC messages
- pizmidi: AudioToCC - Converts audio amplitude (RMS) to CC messages.
CC state:
- pizmidi: midiCCReset - Remembers CC values and sends them out again at selected times.
Generation of MIDI
- SoundHelix - Java
- Políssonos - Java
- Euclidean Pattern Generator - Java - old, MIDI in/out devices not selecting
See also Audio#Algorithmic / generative
- MIDI generator, related to fractions of bpm
- either momentary or toggled.
- passing beats between parts
- harmonyseq can be used to map MIDI events to one shot or repeating notes/chords/patterns, hard to send the tempo float over osc to....
Live recording and looping of MIDI
Software options:
- sequencer64 - no MIDI record control or MIDI learn yet
- harmonySEQ - no recording. sequences and LFOs with multiple patterns, MIDI learn for: sequence toggle/one-shot, note/chord/octave change, pattern change, tempo and sequence sync.
- Multi-Arp - ncurses MIDI looper, beta, TUI with typed commands
- Giada - MIDI/audio looper, limited MIDI mapping
nsm-proxy nsm-seq64 # via nsm-proxy, requires an empty midi file # make sure set to jack transport master
- seq64 - beta features
- variset feature (commandline flag) - allows larger set sizes/dimensions
- indep mainwids feature - allows viewing three sets at a time
- seq64 - part/pattern progression layout and switching process
- follows a mostly vertical direction
- how is set play meant to work? move up/down in column feature request? manual.
- follows a mostly vertical direction
to redo:
- seq64 - MIDI hardware mapping to seq64 MIDI control - see Audio#sequencer64
- start -
- stop - nano stop - cc42
- pause (stop/start toggle) - nano play - cc41
- screen-set up - nano marker > - cc 62
- screen-set down - nano marker < - cc 61
- screen-set play - nano marker set - cc 60
- bpm page down - dj2go left jog - cc#25 - value 127
- bpm page up - dj2go left jog - cc#25 - value 1
- mod thru toggle/on/off -
- mod record -
- mod queue - b4
- mod solo toggle/on/off
- mod replace - c5
- mod snapshot - c#5
- mod group learn - d5
- mod group mute select - d#5
- pattern toggle - 0-31 in sequencer64 - c2 (32)-g4
Kick | Kit | Perc | Bass | Pad | Phrase A 1 | Phrase B 1 | Phrase C 1 |
Kick | Kit | Perc | Bass | Pad | Phrase A 1 | Phrase B 1 | Phrase C 1 |
Kick | Kit | Perc | Bass | Pad | Phrase A 1 | Phrase B 1 | Phrase C 1 |
Kick | Kit | Perc | Bass | Pad | Phrase A 1 | Phrase B 1 | Phrase C 1 |
- midifilter.lv2: MIDI Duplicate Blocker - for live vs. seq64 notes
MIDI automation/apreggiation
Carla:
- CC 2 Breath Controller = Dry Wet
- CC 7 Volume = Volume
- CC 8 Balance = Left/Right
- QMidiArp - standalone and LV2
- MIDI arpeggiator
- programmable step sequencer
- LFO
- transport sync
- preset grid
- Hypercyclic - standalone and VST
- host tempo sync in VST, no Jack Transport sync in standalone.
- pizmidi: midiSimpleLFO - One CC LFO with some "simple" options.
- pizmidi: midiCCModulator - Use one CC to modulate another CC (or note velocity) in various ways.
MIDI velocity scaling
- midifilter.lv2: MIDI Velocity Adjust
- midifilter.lv2: MIDI Velocity Randomization
- midifilter.lv2: MIDI Velocity-Range Filter
- pizmidi: Piz midiVelocityScaler - Scale/reverse/offset velocity of input notes (Note On and/or Note Off).
MIDI gating
- pizmidi: midiCCToggle - For changing momentary CC buttons into toggles.
MIDI delay/loop
- midifilter.lv2: MIDI Delayline
- midifilter.lv2: MIDI N-Tap Delay
- pizmidi: Piz midiDelay
- pizmidi: midiExactDelay
- pizmidi: midiNoteRepeater - Repeats every Nth note a set number of times, or blocks it.
MIDI sostenuto
- midifilter.lv2: MIDI Sostenuto
- pizmidi: midiFingered - Selectively sends standard portamento on/off CC messages to emulate "fingered portamento" for synths that don't have it. For this to work, the target instrument must have a portamento on/off switch that responds to CC 65.
MIDI swing/groove
- pizmidi: midiSwing - Delays and/or offsets velocity of and applies probability to notes (and optionally also CCs) at every other step of a selected note value.
- pizmidi: midiProbability
MIDI key transpose
- midifilter.lv2: MIDI Keys Transpose - Flexible 12-tone map.
- midifilter.lv2: MIDI Chromatic Transpose
- pizmidi: midiForceToKey - no GUI. Scale patches
- pizmidi: midiTranspose - no GUI
MIDI scale alteration/filtering
- midifilter.lv2: MIDI Enforce Scale
- pizmidi: Piz midiScaleChanger - no GUI
- pizmidi: Piz midiBlackKeyFilter
- tonespace - standalone, VST
MIDI chord generation
- midifilter.lv2: MIDI Chord - Harmonizer - midifilter.lv2
- tonespace - standalone, VST
- Piz midiChordHold - ??
- pizmidi: midiNoteGroups - Assign play and/or choke groups to MIDI notes.
- pizmidi: midiChords - Windows VST??
MIDI chord note split
- midifilter.lv2: MIDI Strum - A midi arpeggio effect intended to simulate strumming a stringed instrument (e.g. guitar). A chord is 'collected' and the single notes of the chord are played back spread out over time. The 'Note Collect Timeout' allows for the effect to be played live with midi-keyboard, it compensates for a human not pressing keys at the same point in time. If the effect is used with a sequencer that can send chords with all note-on at the exactly time, it should be set to zero.
- pizmidi: midiStrum - Sequentially delays notes of an input chord to simulate strumming.
MIDI chord channel split
- pizmidi: midiChordSplit - For splitting polyphonic material to multiple midi channels based on selected note ranges for each voice. This is different from a straight keyboard splitter because the ranges can overlap, and the plugin attempts to choose the most appropriate channel.
- chordemux - a MIDI filter/router utility which receives chords on its input channel, routes chords' notes to different channels depending on chord type and inversion
- pizmidi: midiPolyphony - For spreading polyphony across midi channels, i.e. if you play 4 notes, each one will go to a different channel. Polyphony per channel can be set from 1 to 64 notes for more flexibility. You can also use it to convert polyphonic input to monophonic output.
- pizmidi: midiChs_noGUI - Channel filter/changer like energyXT1 "MIDI chs" component.
Synthesis
Soundfont and sample bank
For velocity layers: Hydrogen, DrMr, DrumGizmo, Fabla2, AVLDrumkits
- Sampler (live)
- Fabla2
- Samplers (file based)
- samplv1 - one sample, various pitches. effects but no sample editing.
- drumkv1 - many samples, one pitch. effects but no sample editing.
- Sample slicing
- shuriken - file based beat slicer, MIDI controllable, soundfont generator. no MP3.
- freecycle - file based beat slicer
- Soundfont hosts
- Carla - sf2/sfz/gig host (compiled in fluidsynth backend)
- DrMr - Hydrogen kit based sampler, 16 voices - LV2
- DrumGizmo - drumgizmo format
- AVLDrumkits - self-contained kit soundfonts; Red Zeppelin stereo, Red Zeppelin multi-out, Black Pearl stereo, Black Pearl multi-out - LV2
- Konfyt - additional soundfont and performance management, uses Carla (fluidsynth) as backend
- SFZero - untested
- Hydrogen - multilayer
Drums
- Mixed drum synth
- Stegosaurus - LV2 - hard to use, kick: c4, snare: d4, closed hat: e4, open hat: f4
- DrumSynth - LV2/VST - 32 voices polyphonic, 24 drum notes, 1 tone with sweep, 2 overtones, 2 overtones, envelope editor, midi automatable with learn function
- Rudolf 556 - LV2 - old [2]
- Smack - Ladspa - deps: Ingen, om, omins, and blop, cmt, and swh
- Single drum synth - Win VST
- TW-Opkicker - kick drum
- TW-Percussion1 - 2.5 osc, various presets
- KickMaker - kick drum, 4 osc+envelope plus output envelope - Windows VST. Linux build?
- Mixed drum synth - Win VST
- ErsDrums - drum machine, phat, track mono/stereo and stereo out options
- KMT2 - 8 voices, individual outs, sensitive controls
Bass, pad and lead
- Synths
- Synths w/ host tempo sync
- TAL Noizemak3r - nice - LV2
- triceratops - LV2
- Infamous Cellular Automaton Synth - LV2
- synthv1 - standalone, LV2
- PHASEX - standalone
- Synths w/ host tempo sync - Win VST
- basic65 - chip tune
- Crystal - pad
- Diodow - atmospheric
- dlM entropy
- TheBlooo, TheScrooo
Audio routing and FX
- Audio mixing
- MixerStereoEight - 16 ins and outs, 8 stereo channel control
- AVL Drums Multi out control
- m_mixer_S4toS32 [5] - lv2, 4 stereo to 8 stereo sends each - for fx sends
- AMS Stereo Mixer 8 channels (alsa modular) - lv2, 8 mono to l/r stereo
- AMS Stereo Mixer 2 channels (alsa modular) - lv2, 2 mono to l/r stereo mixdown
- MixerStereoEight - 16 ins and outs, 8 stereo channel control
Used: MixerStereoEight to AMS Stereo Mixer 2 channel
- Audio routing hardware control
- nano2 faders / solos
- dj2go master vol - master vol out
- QWERTY keyboards (main for seq64 and secondary via midikb)
- Mechanism with hotkeys for general mute (+volume?) groups
- drums
- synths
- effects
- Mechanism with hotkeys for effect send trigger/application
- Seq64 patterns for effect automation
- audio level fade change cc pattern
- Visualisation
- x42 Stereo/Frequency Scope
- Ardour channels as hosts has bugs, see section below
- gating, reverb, delay, distortion, filters, etc.
todo:
- box off an fx plugin rack
- delay - cc range filter/alter for fine synced delay time control - tal dub - better plugin for delay time sync (options as spectrum of length, not grouped)?
- gate -
- eq - dj hi/low pass? - dj2go three faders for low mid hi. eq over master out?
- filter -
- autopanner -
- fuck shit up plugin - anarchy rhythms?
Gating
- Gate
- mda Dynamics - lv2, vst
- GT10QM / GT10QS - lv2
- Gates with host tempo sync
- SuperCutSequencer - LV2 - Cut "On/Off" Sequencer (8 steps with smooth) synced to Midi-Clock Beats and Midi-Clock Start/Stop
- dfx skidder - fun but tempo sync doesn't work properly - Win VST
- dlM moot - Win VST
- StormGate1 - Win VST
- dlM gator - meh? - Win VST
- gate3 - meh? - Win VST
Filter
- Filters
- TAL-Filter-2 (filter) - LV2
- ams-lv2, avw.lv2, Fomp, BLOP
- mda: Re-Psycho! - Drum loop pitch changer, RezFilter - Resonant filter with LFO and envelope follower, Round Panner - 3D panner
- Channelswap, MAutopan, Spectral Autopan
- Ducka (side-chain envelope), ndcTrem+ (tremelo), dlM bent (desync), Masha (beat grinder), dfx buffer override (stutter), dlM thrummaschine (distortion) Kitchen Sync (complex LFO), The Modulator 2 (amplitude/ring/frequency modulation), dlM sfilter (sequenced filter), dlM pfilter (probabalistic filter), dlM manic (glitch sampler), Livecut (glitch), Muchacho (stutter), Phase Seq (glitch), dlM truc/2 (multi), Frakture (multi), Hysteresis (multi)
- kn0ck0ut-LV2 - an LV2 plugin to perform spectral subtraction. It can be used to achieve a wide variety of effects, most notably removing or extracting the center of a two channel audio file. As Kn0ck0ut is only a plugin, you will need a host for LV2 plugins in order to use it, such as Ardour, Qtractor, Ingen, jalv, lv2_jack_host, or lv2file.
- ArtyFX
- rkrlv2
- Panoramix - Stereo Panorama/Balance and Volume Automation Tool.
Reverb
- Reverb
- mverb - lv2
- Tal-Reverb-III - all plate reverbs
Distortion
- Distortion
- mod-distortion
- gx_vobtb.lv2 - fuzzbox
- deteriorate-lv2
- Deathcrush
- bitfilter.lv2
- bitrot
Granular
- Granular
- Argotlunar - tempo sync, multiplatform VST
- grANALiser - Windows VST
- 23_words - Host-synced randomised sample player/modulator. Windows VST
- Muchacha - Applies David Haupt's granulator to clock-synced probability sequencer. Windows VST
Pitch shifting
- Pitch shifting:
- talentedhack
- x42-autotune (fat1.lv2)
- TAL-Vocoder
- VocProc
- mod-pitchshifter
- lv2vocoder
Delay
- Delays with host tempo sync:
- TAL-Dub-3 - LV2
- Anarchy Rhythms - Win VST
- Calf Vintage Delay, Calf Reverse Delay, ZamDelay (mono), Della (mono), Leet Delay 2 (Win VST), TigerDelay (Win VST), Spaceship Delay (Win VST), PPD Echobox (Win VST), Tapatiki (Win VST), Delazi (Win VST), Rubbadub (Win VST), KR-Delay FS, SoundHack +delay (Win VST)
Looping
- Looping
- SuperBeatRepeater - Carla doesn't see?
- DeLooper
- beatslash-lv2
- InstaLooper - vst
- Tempo Sync Reverser
- SooperLooper - larger, proper
- Luppp - Ardour-like
EQ
- EQ
- x42-eq - LV2
- Lv2fil - Stereo and mono LV2 plugins, four-band parametric equalisers
- HiLoFilter - vst
Compression
- Compression
- Radium Compressor - over master out
- New Visual Compressor - LV2
Structures
ABAC, etc. with length and intensity as a varying state.
AB either harmonic relation or on/off.
Kick
- 4/4 - variations of
- Swung / offbeat
- Matching bass
Bass
- 8 beats one tone, 8 another
- 64 beats one tone, 64 another
Bugs
(and nitpicks)
- Cannot yet do/use/is annoying
- Session management
- NSM - undeveloped UI, can't delete/move/rename sessions, no delete confirmation, new session/client button confusion, nsm-proxy doesn't save label first time. no jackpatch connection state file save/argument, loses states on bad crash. mostly does its job though..
- i3 - working towards a sound layout save and restore process..
- Carla - plugin state has to be manually loaded, plugin windows need to be manually opened (nsm?) [6]
- Carla - takes a while to close [7]
- Carla - no NSM portability yet [8]
- Routing
- jack2 - lacks Metadata API so no pretty device port names [9]
- Patchage - doesn't auto-refresh when a client changes input/output ports.
- Carla - crashes after a plugin is renamed [10]
- Carla - has a max plugin instantiation limit of 10s, ErsDrums loads only 50% of the time depending on load
- Carla - cannot reorder/group plugins in rack [11]
- MIDI
- MIDI controlled MIDI looping - no software good enough enough yet, would allow live loop of mute and effect changes. seq64 is closest.
- sequencer64 - no MIDI start/stop/arm just yet [12].
- sequencer64 - can't change BPM whilst running yet [13].
- sequencer64 - can't see if text field is active or button is selected (accidental space) in editor window
- Giada - audio/midi looping - problems between nanoKONTROL2s no button off note off CC and parameter scales [14]. fiddly midi control; learn but no 'mod' like sequencer64, i.e., no MIDI 'channel' (sample/sequence) select or channel groups - every item requires unique MIDI CCs and learns for each of it's functions.
- External interactive tempo changes
- klick doesn't do JACK transport and OSC mode (from gtklick) at same time [15]
- Jack Director only has set bpm presets triggerable by midi
- InConcert doesn't take external input or display bpm, crashes often
- DAW
- LMMS - no LinuxVST or LV2 [16]
- Qtractor - doesn't see some VSTs linked by Airwave..
- Qtractor - plugin MIDI ports are exposed through jack "system" block?! name is unuseful "midi_playback_13"
- Qtractor - clicking on a bus option bus not changing it, then clicking another bus prompts to save (no) change
- Qtractor - ERSDrums - on a MIDI track and no audio outs, on a Audio track and no MIDI ins?
- Ardour - can't undo various tasks
- Ardour - "Add New Subgroup Buss" doesn't work
- Ardour - can't create busses in routing page
- Ardour - plugin output channel numbering reversed/whack! (ERSDrums at least)?
- Ardour - no virtual piano to plugin MIDI input for testing
- Ardour - metronome is a fixed pattern, faster would enable quicker beatmatching with external source [17]
- Ardour - no VST tempo sync? :( [18]
- Ardour - no Jack tempo sync! [19] also no MIDI Clock sync [20]
- Ardour or sequencer64 - with seq64 as Jack Transport Masteer, Ardour starts but doesn't use the correct tempo
- Synthesis
- Samples
- petri-foo - broken, always starts from 0 :(
- Shuriken - no mp3 at least until the end of 2017 due to patents [23] [24]
- Shuriken - playback line position becomes incorrect after change to/from Zoom Original scale [25]
- Shuriken - cannot zoom in after enabling or disabling Slice [26]
- Shuriken - sometimes crashes when rearranging samples [27]
- Shuriken - major problems with Export As... feature [28]
- Session management