I tried NoClone when it was in version 3
It is / was good but very s.l.o.w, but did good job of finding duplicates.
I tried the updated more recent versions of NoClone that claim they can find duplicate music files. But it cannot.
At least I dont see how a 6.3 meg mp3 file can be the same as a 2.0 meg mp3 file. The tagger does not make that much difference!!
Recently tried duplicate cleaner 1.4.7 by digitalvolcano.
Seems OK
Like all these programmes, be really careful before deleting. There are always disclaimers - ''you dunit, not me guvnor'' . . . I check the actual subdirectories.