Music Spectrograph 4+

HotPaw Productions

    • 4.5 • 4 Ratings
    • $4.99



HotPaw Piano Roll Music Spectrograph - A Visual Music Transcription Assistant

This is a Mac OS X version of the HotPaw Music Spectrograph app for iOS devices.

Visualize and reverse engineer sound and music. The Music Spectrograph displays music and sound as it might appear on a live piano-roll or MIDI/Music editor. The scrolling graph is of music pitch frequencies versus time. This form of sound visualization can assist with the transcription of music (but only if you ignore harmonics and overtone frequencies). In addition, you can also slow down the audio play rate to make it even easier to transcribe music, or even freeze music in time, using a built-in custom audio re-synthesis mode.

The HotPaw Musical Piano Roll Spectrograph creates a scrolling 12th-octave MIDI pitch-centered spectrogram, either from microphone input or synchronized with playing a sound or music file. To analyze a song in your iTunes library, hit the "Pick Tune" button and choose a music file. Hit the "Use Mic" button on the Music Control panel to switch back to analyzing live audio.

Features include:
- 12th-octave MIDI-pitch-centered spectrograph (also called a sonogram)
- Speed up or slow down music play, or even freeze sound in time.
- Color frequencies to see if they are in-tune or out-of-tune
- Color frequencies for loudness, or graph in black-and-white

Music playback during spectrograph analysis is monophonic only, as only 1 channel is visualized. To help remove vocals on many common pop tune mixes, you can select L-R in the Tunes display. The current version of the Music Spectrograph application is limited to up to 10 minutes in length of music for MIDI visualization. Not all iTunes file formats supported. DRM protected music files are not supported.

Please Note: For most musical sounds, you will see LOTS of overtones and harmonics, not just the fundamental note pitch frequencies. Some musical expertise will be required to separate the actual notes from among this series of overtones. Drums and percussion in common pop, rock, and jazz music can also fill the spectrum with wideband noise that can hide the pitch of other instruments, including any melody.

What’s New

Version 1.2.4

Stability and performance improvements for new Mac hardware and new macOS updates

Ratings and Reviews

4.5 out of 5
4 Ratings

4 Ratings

ElroyCat ,

A really nice sound tool

I get a lot of good sound information from this easy to use tool. I like to be able to SEE the audio when configuring an audio system. This tool gets you a long way into that process quickly.

Since it is easy to use, you can instantly see if something is wrong.

Schwitters ,

Nice spectrogram display, great for teaching

I teach courses related to the psychology of music, and this is one of the best applications of this sort that I have encountered.
I use these sorts of programs to illustrate harmonics — what aspects of the spectrum change with different periodicity (pitch) and spectral shapes (timbres).
It’s also fun to look at the running frequency content of music, especially music with vocals.

1) very easy to use (unlike many other spectrogram programs where one must find the right parameters to effectively display music),
2) the display is beautiful,
3) it can play music files (I have only tried MP3) or use microphone input
4) there is a spectrum analyzer window that shows the spectrum at each moment.
5) it seems to run flawlessly, have not had a crash thus far
6) it tracks individual harmonics very well
7) one can speed up or slow down recorded music tracks (0.12x - 3x)
8) the 5kHz frequency cutoff for the spectrogram is appropriate for music visualization
9) piano keyboard mapped to spectrogram allows identification of particular note fundamental frequencies (F0s) for transcription purposes

1) an oscilloscope window with triggering and time window parameters judiciously chosen for music (say a window of 50 ms duration) would be nice
2) the automatic gain control is great, but some sort of robust or adaptive scaling of the spectrogram gain would be desirable — one manually adjusts the gain to show the features one wants to visualize
3) It wasn’t clear what one or two of the controls do (labels might help)
4) I would also add a running short-time autocorrelation window (lags of 0-50 ms) to show pitch (F0)

App Privacy

The developer, HotPaw Productions, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

More By This Developer

Morse Words
inTuna Bass Strobe Tuner
Say Color
inTuna Strobe Guitar Tuner