PocketMIDI: MIDI Keyboard

PocketMIDI is a free, low-latency MIDI synthesizer and piano app for Android, built for live performance.

Whether you're connecting a USB MIDI keyboard on stage or playing the on-screen piano keyboard, PocketMIDI delivers studio-quality sound with a latency target of under 40 ms — fully offline, no ads, no tracking.

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INSTRUMENTS
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• Grand Piano — Salamander Grand Piano V3 (Alexander Holm), 30 root notes spanning the full 88-key range (A0–C8), OGG Vorbis samples.
• Strings — rich, expressive orchestral strings with natural attack and release.
• Dark Pad — lush, atmospheric pad for ambient and cinematic performance.
• Synthesizer — built-in digital synthesizer with PolyBLEP waveforms (sine, saw, square, triangle), full ADSR envelope, and a state-variable filter.

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USB MIDI KEYBOARD SUPPORT
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Connect any class-compliant USB MIDI keyboard via OTG adapter. PocketMIDI automatically detects the device and routes MIDI note on/off and sustain pedal (CC64) events directly to the audio engine with minimal overhead.

• Auto-launch when a keyboard is connected (optional)
• Full polyphony: up to 96 simultaneous voices (64 sample + 32 synth)
• Velocity sensitivity and sustain pedal support

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ON-SCREEN KEYBOARD
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• 2-octave multi-touch piano keyboard (C3–C5)
• Up to 10 simultaneous touches for polyphonic playing
• Velocity-sensitive: tap position affects note velocity
• Amber highlight on pressed keys

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ARPEGGIATOR
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• Selectable patterns, rates (including triplets), octave span, gate, and latch
• Auto-plays as you hold keys — tap Latch to keep it running hands-free
• Tap-to-type BPM input, synced with the metronome
• Chord mode: tap chord buttons while playing to trigger full chords and arpeggios in real time

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SYNTH EDITOR
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When the Synthesizer instrument is selected, a full synth editor is available:
• Waveform selector: Sine, Saw, Square, Triangle
• ADSR envelope: Attack (1 ms–4 s), Decay (1 ms–4 s), Sustain (0–100%), Release (1 ms–8 s)
• Low-pass filter: Cutoff and Resonance

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PRESETS
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• Save your favourite instrument and synth settings as named presets
• Load presets instantly during a performance
• Export all presets to a JSON file and share via any app
• Import presets from a JSON file

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MIDI RECORDING
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• Record everything you play and review it in a real-time piano roll
• Fixed-timeline playback with moving playhead; pinch-to-zoom and pan

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METRONOME
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• Built-in click track: 20–300 BPM
• Time signatures: 2/4, 3/4, 4/4, 6/8, 7/8, 5/4
• Visual pulse animation on the status bar

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PERFORMANCE & SETTINGS
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• Real-time performance monitor: active voices, buffer size, sample rate, estimated latency, buffer underruns
• Fully offline — no internet connection required, no ads, no tracking

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TECHNICAL
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• Audio engine: Oboe 1.9.0 (AAudio with OpenSL ES fallback)
• Audio buffer: ~4 ms @ 192 frames, 48 kHz
• Automatic stream restart with exponential backoff
• Minimum Android 8.0 (API 26)

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ATTRIBUTIONS
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Salamander Grand Piano V3 samples by Alexander Holm are used under the Creative Commons Attribution 3.0 license (CC BY 3.0). No modifications were made to the samples.
https://creativecommons.org/licenses/by/3.0/