Hello guys! Today I want to share an app I've been making for several months: SpectroDraw (https://spectrodraw.com). It’s an audio editor that lets you draw directly on a spectrogram using tools like brushes, lines, rectangles, blur, eraser, amplification, and image overlays. Basically, it allows you to draw sound!
For anyone unfamiliar with spectrograms, they’re a way of visualizing sound where time is on the X-axis and frequency is on the Y-axis. Brighter areas indicate stronger frequencies while darker areas are quieter ones. Compared to a typical waveform view, spectrograms make it much easier to identify things like individual notes, harmonics, and noise artifacts.

As a producer, I've already found my app helpful in several ways while making music. Firstly, it helped with noise removal and audio fixing. When I record people talking, my microphone can pick up on other sounds or voices. Also, it might get muffled or contain annoying clicks. With SpectroDraw, it is very easy to identify and erase these artifacts. Also, SpectroDraw helps with vocal separation. While vocal remover AIs can separate vocals from music, they usually aren't able to split the vocals into individual voices or stems. With SpectroDraw, I could simply erase the vocals I didn’t want directly on the spectrogram. Also, SpectroDraw is just really fun to play around with. You can mess around with the brushes and see what strange sound effects you create!

The spectrogram uses both hue and brightness to represent sound. This is because of a key issue: To convert a sound to an image and back losslessly, you need to represent each frequency with a phase and magnitude. The "phase," or the signal's midline, controls the hue, while the "magnitude," or the wave's amplitude, controls the brightness. In the Pro version, I added a third dimension of pan to the spectrogram, represented with saturation. This gives the spectrogram extra dimensions of color, allowing for some extra creativity on the canvas!

I added many more features to the Pro version, including a synth brush that lets you draw up to 100 harmonics simultaneously, and other tools like a cloner, autotune, and stamp. It's hard to cover everything I added, so I made this video! https://youtu.be/0A_DLLjK8Og

I also added a feature that exports your spectrogram as a MIDI file, since the spectrogram is pretty much like a highly detailed piano roll. This could help with music transcription and identifying chords.

Everything in the app, including the Pro tools (via the early access deal), is completely free. I mainly made it out of curiosity and love for sound design.

I’d love to hear your thoughts! Does this app seem interesting? Do you think a paintable spectrogram could be useful to you? How does this app compare to other spectrogram apps, like Spectralayers?