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stk
The Synthesis ToolKit in C++ (STK) is a set of open source audio signal processing and algorithmic synthesis classes written in the C++ programming language.
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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Did you have a look at e.g. ChucK, SuperCollider, Csound, Faust, just to name a few. Or there is e.g. the Synthesis Toolkit (see https://ccrma.stanford.edu/software/stk/) which has a Lua binding (see https://sourceforge.net/projects/stkwrap/).
Just googled, see e.g. https://github.com/graue/luasynth and https://scott.mn/projects/luasynth.html. Results look decently.
NOTE:
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Hence, a higher number means a more popular project.