PocketMIDI — Professional Low-Latency MIDI Synthesizer for Android

What's Inside

Everything You Need to Perform Live

From studio-quality samples to a built-in synthesizer — all offline, all free.

4 Instruments

Grand Piano (Salamander V3), Orchestral Strings, Dark Pad, and a digital Synthesizer with PolyBLEP waveforms.

USB MIDI Keyboard

Auto-detects class-compliant USB keyboards via OTG. Full velocity, polyphony (96 voices), and sustain pedal (CC64).

On-Screen Keyboard

2-octave multi-touch piano (C3–C5). Up to 10 simultaneous touches. Velocity-sensitive tap position with amber key highlights.

Synth Editor

Full ADSR envelope, low-pass filter (cutoff + resonance), and waveform selector: Sine, Saw, Square, Triangle.

Arpeggiator

7 modes (Up, Down, Up-Down, Random…), 7 rates from 1/4 to 1/16T, 1–4 octave span, adjustable gate, and tap tempo.

Zero Friction

Plug In.
Play Instantly.

Connect a USB MIDI keyboard and PocketMIDI launches automatically — no tapping, no pairing, no setup screens. Your keyboard is live the moment it connects.

1 Plug your USB MIDI keyboard into your phone via OTG adapter

2 PocketMIDI launches automatically — Android OS triggers it

3 Start playing — zero taps, zero configuration

Auto-launched. No taps required.

In Action

See PocketMIDI in Action

PocketMIDI main screen with on-screen piano keyboard

Playing note chords on the on-screen keyboard

Synthesizer performance screen with ADSR controls

Built-in metronome with BPM and time signature controls

Instrument selector showing piano, strings, pad, and synthesizer

Arpeggiator tab with tempo, octave span and rate controls

Arpeggiator mode selector showing Up, Down, Up-Down, Random and As Played patterns

Playing chords using a USB MIDI keyboard connected to Android

USB MIDI Keyboard Support

Play With a Real Keyboard

Connect any class-compliant USB MIDI keyboard via a standard OTG adapter. PocketMIDI automatically detects the device and routes MIDI events directly to the audio engine with minimal overhead.

Auto-launch when keyboard is connected (optional)
Up to 96 simultaneous voices (64 sample + 32 synth)
Full velocity sensitivity and sustain pedal (CC64)
Works with any class-compliant USB MIDI device

Synthesizer editor with waveform selector and ADSR controls

Built-in Synthesizer

Shape Your Sound

The built-in digital synthesizer features PolyBLEP anti-aliased waveforms, a full ADSR envelope, and a state-variable low-pass filter — all with real-time, glitch-free parameter changes.

Waveforms: Sine, Saw, Square, Triangle
ADSR: Attack 1ms–4s, Decay 1ms–4s, Sustain 0–100%, Release 1ms–8s
Low-pass filter with Cutoff and Resonance
Save and load synth patches as named presets

Built-in Metronome

Practise With a Click Track

The integrated metronome uses the same low-latency Oboe audio engine as the synthesizer — so the click and your playing are perfectly in sync.

20–300 BPM with tap-tempo or drag control
Time signatures: 2/4, 3/4, 4/4, 6/8, 7/8, 5/4
Visual pulse animation on the status bar
Accent on beat one — audible and visual

Arpeggiator screen showing tempo, octave span and rate controls

Built-in Arpeggiator

Patterns That Play Themselves

Hold a chord and let the arpeggiator do the work. Choose a pattern, set your rate, dial in the gate, and the arpeggiator turns static notes into dynamic, rhythmic motion — all synced to a precise tempo.

7 modes: Up, Down, Up-Down, Down-Up, Random, As Played
7 rates: 1/4, 1/8, 1/16, 1/32 and triplet variants (1/4T, 1/8T, 1/16T)
1–4 octave span to broaden or tighten the range
Gate slider from Staccato to Legato — tap tempo or BPM dial

Professional Low-Latency MIDI Synthesizer for Android