PortAudio might be a bit more popular than Composer's Sketchpad. We know about 1 link to it since March 2021 and only 1 link to Composer's Sketchpad. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
In case anyone is interested, I played around with a novel musical notation paradigm a few years ago in the form of an iPad app: http://composerssketchpad.com Basically, you draw pitches directly on a horizontally-infinite canvas. By default, pitches stick to equal temperament gridlines, but you can turn off this snapping if you want to (for example) play around with a different tuning or annotate a bendy guitar... - Source: Hacker News / 4 months ago
FYI PyAudio built on this software: http://portaudio.com/ which interfaces directly with Alsa/OSS (refer to the sounds system page, I'm not saying Open-Source Software here) which PulseAudio also does. Source: about 3 years ago
Soundbow - Create music by drawing curves over the screen.
JUCE - JUCE is a wide-ranging C++ class library for building rich cross-platform applications and plugins...
noise.sh - Excel for music producers and sound designers
RtAudio - RtAudio is a set of C++ classes that provide a common API for realtime audio input/output across...
Helio - Design successful products by revealing key user behaviors
OpenAL Soft - OpenAL Soft is an LGPL-licensed, cross-platform, software implementation of the OpenAL 3D audio API.