Mojave introduced some interesting contextual editing features to Quick Look. Quick Look was already handy for viewing disparate types of files in the Finder by pressing the Space Bar while a file was selected. Now, depending on the type file being viewed in Quick Look, various editing widgets will be made available.
I was very surprised when Apple first demo'd Quick Look in Mojave and saw that audio editing was a possibility. Albeit, it's just simple trimming—that is, audio can be removed from the beginning and/or ending of an audio file—but it might prove handy.
A few years ago I posted an AppleScript wrapper for the qlmanage command line tool, called Have a Quick Look. It allows you to select a track in iTunes and display a Quick Look panel of the selected track's file. A trifle, really.
But now that Quick Look has this new editing feature, Have a Quick Look could be a slightly handier tool. Here is a track from one of my "Live At Leeds" albums by The Who, which I have selected in iTunes and then run Have a Quick Look on. Pete Townshend famously talks a lot before each song. Now, I can trim that part out (sorry, Pete):
You can see the :40 seconds of Pete pontificating at the start of the track
Optimally, this sort of editing should be done with a Real Audio Editor. But if you're just fixin' Voice Memos (which can be added to iTunes by dragging from the Marzipan Voice Memos app) or something like that, I suppose this could be helpful.