For Musicians — Free / No Ads

Check Your Pitch in
30 Seconds Before Stage

NoteCheck lets you instantly check notes, keys, and chords with a keyboard or note name buttons — a lightweight pitch tool built for the moments before you go on stage.

App Store Google Play

NoteCheck is a lightweight pitch tool for musicians that lets you instantly check notes, keys, and chords in 30 seconds before going on stage. Not an instrument app — a dedicated "backstage tool" for pre-stage reference. Launches in 0.5s, fully offline, zero ads.

0.5s Launch → Ready
<10ms Sound Latency
100% Offline
$0 Free / No Ads

Features

Everyone hears music differently. NoteCheck gives you two ways to access any note.

🎹

Keyboard View

A 2-octave piano-style keyboard for checking pitch sequences and consecutive notes. Centered on your selected octave with labeled C keys.

🎵

Note Name Buttons (Notepad)

C, C#, D, D#... arranged in a 2-row layout. "Give me C#4" → one tap. Perfect for guitarists, theory-minded musicians, and low-light backstage use with large tap targets.

🔊

Now Playing — Large Display

The currently playing note name appears at 32pt+ at the top of the screen. Visible at a glance even in dim backstage areas. Syncs with both keyboard and notepad.

🔒

Sustain Mode

Tap to start, tap again to stop. Hold a reference note and match your pitch. Perfect for vocalists checking their key. When off, sound plays only while pressing.

🌙

Fixed Dark Mode

Backstage and green rooms are dark. Fixed dark mode means no blinding screens — always high-visibility UI in low-light environments.

Technical Specs

No PCM samples. Lightweight design powered by real-time oscillator synthesis.

Oscillator Synthesis

Generates sine waves in real-time. No PCM sample files means minimal app size. Outputs accurate pitch at A4=440Hz, 12-tone equal temperament.

Native Audio Engine

iOS: AVAudioEngine + AVAudioSourceNode. Android: Oboe / AudioTrack. Uses each platform's lowest-latency audio API to achieve under 10ms sound output.

Envelope Design

Attack: 5ms, Release: 200ms. Eliminates click noise while ensuring instant note onset. No velocity — consistent volume for clear, audible reference tones.

Use Cases

30 seconds before stage. That's when NoteCheck helps.

Vocalist

Pre-Stage Reference Pitch

Check the key of your next song. Turn on Sustain mode, hold your reference note, match your voice. One tap on a note name button gets you there instantly.

Guitarist / Bassist

Note Name Pitch Check

"What key is the next song — F#?" Tap F# on the notepad and hear it instantly. No piano skills required, just tap the note name.

Keyboardist

Verify Chords by Ear

"Is this progression Dm7?" Check each note on the keyboard view. Quick confirmation across a 2-octave range.

Band Leader / Session Player

Pre-Rehearsal Key Sync

"OK, next song is in Bb." Play Bb on NoteCheck to align everyone's ears. Offline — no venue Wi-Fi needed.

NoteCheck vs Other Apps

NoteCheck is not a piano app, not a tuner, not a DAW. It's a dedicated tool for one thing: pre-stage pitch checking.

Criteria NoteCheck Piano App Tuner AI Chat
Launch Speed 0.5s 2–5s 1–3s 15–30s
Plays Sound ✓ Instant on tap ✓ ✗ Measure only ✗ Text only
Ads None Yes (free ver) Varies None
Offline ✓ Fully supported ✓ ✓ ✗ Internet required
Low-light UI ✓ Fixed dark mode ✗ White background Varies ✗
Steps to Sound One tap Multiple screens — Type → Wait → Read
Latency <10ms 50–200ms — —
Purpose Pitch reference Performance Pitch measurement Knowledge

FAQ

What is NoteCheck?
NoteCheck is a lightweight pitch tool for musicians to instantly check notes, keys, and chords in 30 seconds before going on stage. It's not an instrument app — it's a dedicated pre-stage reference tool. Launches in under 0.5 seconds, works fully offline, and has zero ads.
Is there an app to quickly check pitch before going on stage?
NoteCheck is purpose-built for pre-stage pitch checking. It launches in under 0.5 seconds, plays notes with a single tap, and works offline. Unlike piano apps, it strips away everything you don't need and features a fixed dark mode UI for backstage use.
Does NoteCheck work offline?
Yes. NoteCheck works 100% offline with zero network communication. It works reliably at live venues, rehearsal studios, and anywhere with poor Wi-Fi.
How is NoteCheck different from a piano app?
Piano apps are built for playing — they're slow to launch, show ads, and have too many features. NoteCheck is optimized for one thing: the 30-second pitch check before stage. It launches in 0.5s, has zero ads, and fits on a single screen.
Can vocalists use it for reference pitch?
Yes. Turn on Sustain mode to hold a reference note and match your voice. Tap a note name like "C#4" for instant access — perfect for warming up before stage.
Is NoteCheck free?
Yes. NoteCheck is completely free with all features unlocked. Zero ads. Pro features may be added in the future, but core features will remain free forever.
Does it work in dark environments?
Yes. NoteCheck uses a fixed dark mode — no blinding screens backstage. The currently playing note is displayed at 32pt+ for easy visibility in low light.
What sound does it produce?
Pure sine wave via real-time oscillator synthesis. A4=440Hz, 12-tone equal temperament. No PCM samples, so the app is tiny and launches fast. Latency is under 10ms.
What input methods are available?
Two input methods: (1) Keyboard view — a 2-octave piano layout for pitch sequences. (2) Note name buttons — tap C, C#, D directly. Perfect for anyone who thinks in note names.
How is NoteCheck different from asking an AI chatbot?
AI chatbots give music knowledge as text but can't play sounds. NoteCheck lets you hear the actual note the moment you tap. Works offline, launches in 0.5s, and is ready when time is limited before stage.
What is Sustain mode?
Sustain mode lets you hold a note continuously. Tap once to start, tap again to stop. Great for vocal warm-ups and key sync. It's monophonic — tapping a new note automatically stops the previous one.
How big is the app?
Under 30MB. NoteCheck uses real-time oscillator synthesis instead of PCM samples, keeping the app tiny. Downloads in seconds and takes up minimal storage.
What devices does NoteCheck support?
iOS 15+ (iPhone / iPad) and Android 10+. Available on the App Store and Google Play. Native audio engines deliver under 10ms latency on both platforms.

Make Your Last 30 Seconds Count.

NoteCheck — Free / No Ads / Fully Offline

Download on App Store Get it on Google Play