Music Spectrograph vs variStretch
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Music Spectrograph
Visually reverse engineer sound and music in real-time with a live MIDI piano roll displaying pitch and frequency. Slow down or stop audio to analyze musical patterns, aiding in music transcription and learning.
- Real-time MIDI piano roll
- Pitch and frequency visualization
- Slow down and stop audio
- Music transcription aid
- Adjustable playback speed
- Color-coded pitch graph
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Music Spectrograph allows you to visually reverse engineer sound and music, in real-time. See a live MIDI piano roll showing pitch and frequency. When playing music files, you can slow down, and even stop sound in time. Music Spectrograph is being using in college music programs to aid in learning music transcription. The Hotpaw Music Spectrograph presents a high-resolution scrolling spectrogram as you listen, so that you can see these patterns in sound and music, as well as how sound corresponds to notes on a piano keyboard. This piano alignment makes it far easier to spot which frequencies in sounds correspond to which musical notes. Features include: - 12th-octave MIDI-pitch-centered spectrograph (also called a sonogram) - Usable with live audio, tunes from your iOS device's music library, or a file downloaded via a URL (web address) - Records up to a 4 minute spectrograph history you can stop, scroll back and review - Slow Down music files by up to 8X, or speed music up by 3X to skip sections faster - Stop music in time, and still hear the music frequencies present via re-synthesis (scroll back a little in time to bring up the ReSynth switch). - Play tunes in mono, left or right channel only, or with center-panned vocals reduced - Color the pitch graph to see if notes are in-tune or out-of-tune - Color the spectrograph for loudness, or graph in black-and-white or with Pastel colors - Mid-pitch filtering to remove some of the higher overtones Use the Input? button to select a tune from your library (DRM protected iTunes files not supported). Use the Gear button to select among several viewing modes. There's a volume control to manually set the sensitivity threshold. Stop playing or recording to scroll back and review or resynthesize sound. Touch the keyboard during resynthesis to isolate one note. For many musical sounds, this app will show you many overtones and harmonics, not just the fundamental pitch of notes. Some musical experience is required to tell musical notes from their overtones and harmonic frequencies.
variStretch
This app allows real-time audio speed manipulation without altering pitch. It offers three distinct playback modes and adjustable buffer settings for precise control over sound processing.
- Real-time speed adjustment (0.5-2.0x)
- Tape mode (speed & pitch change)
- Phase Vocoder mode (speed only)
- Adjustable buffer size
- Buffer clear function
- AUv3 host compatibility
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Concept: The app is a so-called time-stretch machine. The user can change the speed (0.5-2.0) of audio source in real-time using keyboard or slider at will. Usage: There are three play modes: 1) Tape (to change the both speed & pitch) 2) Phase Vocoder (to change the speed alone) 3) Thru (no processing) "Buffer Size" slider determines how long the data will be stored. "Buffer Clear" button will reset the buffer to be zero. System Requirements: AUv3 host
Screenshots
Verdict
The clearest difference is rating: variStretch at 5.0 against Music Spectrograph's 2.5. variStretch also leads on price ($5.99 vs $9.99). Music Spectrograph's advantage is update cadence (every 6 weeks vs every 7 months) and ratings volume (4 vs 1). On ads, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Music Spectrograph costs $9.99 and variStretch $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.
variStretch holds the better App Store score, 5.0 against 2.5. Both are backed by a comparable volume of ratings — 4 and 1 respectively.
Music Spectrograph ships an update every 6 weeks, variStretch every 7 months. The most recent releases landed on October 17, 2026 and October 18, 2026 respectively.
| Parameter | Music Spectrograph | variStretch |
|---|---|---|
| Price | $9.99 | $5.99 — better |
| Rating | 2.5 (4 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 4 — better | 1 |
| Update frequency | Every 6 weeks — better | Every 7 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.4 | 12.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | HotPaw Productions | Satoshi Kajii |
Customer experience
Music Spectrograph
variStretch
In-app purchases
Music Spectrograph
No in-app purchases
variStretch
No in-app purchases
Questions
Is Music Spectrograph free?
Is variStretch free?
Which has better reviews, Music Spectrograph or variStretch?
Do Music Spectrograph or variStretch have ads?
Which is updated more often, Music Spectrograph or variStretch?
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