My current favorite is OpusModus https://www.opusmodus.com. It is a commercial app, which will dissapoint some, but is worth the price to me for the level of quality and capabilities. As an added bonus, it is written in Lisp, can be extended using Lisp and uses a S-expression DSL for composition. The development environment has a REPL and a variety of interfaces for composing and exploring music.

For a musical Lisp, personally I prefer extempore: https://github.com/digego/extempore