Sequencing Options for midi in Juce

If one wants to start seriously playing around with midi data in a sequence (transposition, changing/deleting certain notes etc) and creating multiple sequences, it seems there is limited functionality within the core code.

Are there any juce built OSS small libraries out there which add extra functionality rather than having to write from scratch?

If not, what alternatives to people use? Use TSE3 and then passs into juce? [and would this even be sensible to contemplate?]

Any help much appreciated rather than having to rewrite what I’m sure must have been done multiple times. Thank you.