New Project: Rusty Pipes
What is Rusty Pipes
Rusty Pipes is basically a MIDI controlled sample player. It's specifically designed to play sample sets of church and concert pipe organs. The technical term is a Virtual Pipe Organ (VPO). Because organs are typically very large, very immobile, and very expensive, it can be challenging to find an instrument to practice on. Rusty Pipes lets you practice and enjoy whatever Organ you like (and can get a sample set of) in the comfort of your home. Of course this isn't just for practice, organs just sound amazing and are fun to play.
Download and sample music
Rusty Pipes is available for Linux, Mac and Windows, and can be downloaded for free at https://rusty-pipes.com
There you can also listen to a number of sample recordings in Ogg and Flac format.
Why make a new VPO
There are similar programs, like Hauptwerk (Commercial) and GrandOrgue (Open Source). However, Hauptwerk is way too expensive for what it does, requires intrusive DRM, and has the nasty tendency of anti-consumer business practices. GrandOrgue on the other hand is free and open source - but it's written in C, using a codebase inherited from Milan Digital Audio (the makers of Hauptwerk), and it has to load all samples of the organ into RAM, leading to weird stopgap solutions like just not loading all stops.
In fact, I was unable to load the "Friesach" organ on a notebook that had 20GB RAM free to use, and I'm not the only one. So I took matters into my own hands and developed my own VPO software from scratch in Rust, as free and open source software licensed under the GPLv2.
What makes Rusty Pipes special
Rusty Pipes features a very efficient sample streaming method that loads only the first few milliseconds of every sample into RAM, and streams the rest from your SSD. If desired it can also pre-load everything into RAM of course. Aside from this, the program features convolution reverb, synthesized tremulant, powerful MIDI channel configuration and routing, organ stop presets, MIDI file playback and recording, audio recording, a graphical and text mode user interface, high-quality and high-performance 32-bit internal audio mixing that uses modern CPU features like SIMD, it has a REST API for controlling your organ via custom-built consoles, it's available for all major operating systems and platforms, is translated in 29 languages including Latin and Klingon, and the software download is around 10 Megabytes.
Most importantly: Rusty Pipes can load both GrandOrgue and Hauptwerk sample sets.
Where to get sample sets
There's several sources, but you can get high quality free sample sets for GrandOrgue and Hauptwerk at Pietr Grabowski's Site I especially recommend "Friesach" since it's an instrument that combines baroque and french romanticim in one instrument.
Text mode UI
Yes, for running this on less powerful systems, or if you just prefer working in the console, you can run Rusty Pipes with the "--tui" parameter and activate the text mode UI made with Ratatui.
Sourcecode
You can get the code on Github. Contributions are welcome!
Thoughts on using Rust for audio and MIDI applications
The basic functionality of loading and playing GrandOrgue sample sets using MIDI control was implemented in just under a week and with less than 2000 lines of code. Rust has proven to be highly efficient for audio mixing, and the current Rust compiler versions automatically make use of SIMD as long as certain rules are observed, like removing conditions that would introduce branching. Both MIDI (Midly) and audio libraries (Cpal) are very mature and work well across platforms. The user interface initially started out with just a Ratatui text UI, but lateron egui was added. Over the course of two months the code grew to over 9000 lines of Rust code. I have done my best to make the codebase clean and maintainable in the hope that others can build on this foundation.
VPOs are niche software, with several high-price commercial offerings and only one open source project. Now there's two free and open source solutions. With RAM prices exploding, I hope Rusty Pipes can help users who can't afford 64GB RAM just to play a big organ sample set.