Bebop goes past faster than any ear can follow

That is not a failure of your ear — it is a failure of the playback. Take a chorus down to 50 % and the line stops being a blur: the articulation, the ghosted notes, the way the phrase leans across the bar all become audible, and the key never moves, so what you learn slow is what you finger at tempo. Loop the four bars that keep beating you and drill them until they are yours, then creep the speed back up through the presets.

A detail worth knowing: the fine-tune trim matters more on sax than almost anywhere. Plenty of great records were cut a shade off concert pitch, and a few cents of adjustment is the difference between playing along comfortably and fighting the recording all afternoon. Everything else SlowBird does — the searchable library, the per-track memory, the five-band EQ — is on the main page, and the core tools in depth under slow down, looping and notes.

macOS 14 or later · Windows 10 or later · one licence covers both