Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
Fresh install of Catalina. What a difference.
My MacBook has been struggling with Catalina and the performance was so poor i considered reverting back to Mojave. My MacBook pro shipped with El Capitan and I've been upgrading ever since.
So I bit the bullet. I backed up everything. Did an internet install of the OS the MacBook shipped with (El Capitan) and then installed Catalina straight after. What a difference. It's like getting a new mac. Reboots now are fast and the interface is now snappy. No more spinning beach balls.
It's a pain but well worth it.