Comparison

Music Spectrograph vs Chorus Lesson

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • Real-time MIDI piano roll
  • Pitch and frequency visualization
  • Slow down and stop audio
  • Music transcription aid
  • Adjustable playback speed
  • Color-coded pitch graph
Features
Read full description

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.

About

Chorus Lesson

This app functions as a MIDI player designed for personal choral practice. It allows users to isolate individual parts, adjust volume and panning, and change playback speed for tailored practice sessions. Standard MIDI files can be played, with additional song data available for purchase.

Highlights
  • MIDI player for choral practice
  • Mute, solo, volume, panning per part
  • Adjustable playback speed
  • Play standard MIDI files
  • Purchase song data in-app
Features
Read full description

Chorus Lesson is a kind of MIDI player, build for the use of personal lesson of chorus. The app allows you set mute, soloed, volume, panning and instrument for each part. You may check your melody line by enabling only your part. Then, sing hearing the overall flow and sound of other parts. You may also change the playing speed, you can practice your part carefully at your suitable tempo. You can play standard MIDI files with this app. In addition, we have a Song Data Shop in this app. You can purchase and download song data in-app purchase. These songs in the shop are originally created for use with this app. Currently, the number of songs is small, but we will gradually increase it. * Some MIDI files may not be played well because of too many parts in the file. We assume a midi file contains five to six parts of SATB and accompaniment piano + some more parts. And we recommend MIDI file of format type 1, although you may still use type 0. Interchangeablitiy: We have tested MIDI files generated by applications belows and some unknown apps. Finale(mac) Notion(iPad) Nanostudio2(iPad) Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Music Spectrograph2 screens
Chorus Lesson4 screens

Verdict

The call

The clearest difference is review sentiment: Music Spectrograph at 50% against Chorus Lesson's 0%. Music Spectrograph also leads on in-app purchases (none vs 10) and device support (3 vs 1). Chorus Lesson's advantage is price ($2.99 vs $9.99) and update cadence (every 2 weeks vs every 6 weeks). On ads 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

CostPrice · In-app purchases · Ads · Monetization

Music Spectrograph costs $9.99 and Chorus Lesson $2.99 up front. Chorus Lesson sells 10 one-off in-app purchases. Music Spectrograph asks for nothing beyond the download.

UpkeepUpdate frequency

Music Spectrograph ships an update every 6 weeks, Chorus Lesson every 2 weeks. The most recent releases landed on October 17, 2026 and October 16, 2026 respectively.

Scorecard7 real differences · 3 level
Music Spectrograph versus Chorus Lesson: the parameters behind the verdict, then further details
ParameterMusic SpectrographChorus Lesson
Price$9.99$2.99 — better
Rating2.5 (4 ratings) — better—
Positive reviews50.0% of reviews — better0.0% of reviews
Number of ratings4 — better—
Update frequencyEvery 6 weeksEvery 2 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS12.4 — better26.0
Further details — not scored
Size1 MB228 MB
Age rating4+4+
DeveloperHotPaw ProductionsNOKKEUSI Inc.

Customer experience

Music Spectrograph

All ratings4 ratings
Positive25.0%
Neutral25.0%
Negative50.0%
Written reviews8 reviews
Positive50.0%
Neutral12.5%
Negative37.5%

Chorus Lesson

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Music Spectrograph

No in-app purchases

10 purchases

Chorus Lesson

One-time10
  • 30-days Trial for freeFree
  • BWV227 All throughFree
  • BWV226-1 Bars 1-145Free
Show 7 more
  • Trial for 14 daysFree
  • BWV226-2 Bars146-244$0.99
  • BWV226-3 Bars245-268$0.99
  • BWV226 Complete set$0.99
  • BWV225 Complete set$0.99
  • BWV228; Fürchte dich nicht,...$0.99
  • BWV229; Komm, Jesu, komm$0.99

Questions

Is Music Spectrograph free?
Music Spectrograph costs $9.99, with no in-app purchases.
Is Chorus Lesson free?
Chorus Lesson costs $2.99, and also offers in-app purchases.
Do Music Spectrograph or Chorus Lesson have ads?
Neither Music Spectrograph nor Chorus Lesson shows ads.
Which is updated more often, Music Spectrograph or Chorus Lesson?
Music Spectrograph ships an update every 6 weeks, and Chorus Lesson every 2 weeks. Most recently, Music Spectrograph was updated on October 17, 2026 and Chorus Lesson on October 16, 2026.

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