Yep - C++ is generally used for audio programming because you can write code that is real time safe for use on the audio thread (low latencies mean you might have 5ms to fill a buffer with fairly intense calculations required for a modern synth, so any waiting for locks, memory allocation, GC pauses etc. can be disastrous and lead to audible glitches). On top of that there’s a huge amount of code and libraries for audio stuff written in C++ - we used JUCE which provides a lot of helpful abstractions and cross platform compatibility.