The Amazing Slowdowner is an app from Roni Music. Its been around for a very long time. Essentially it allows you to slow down a song without changing the pitch. As an example you can isolate a part of a song, slow it down to any speed and loop it for as long as it takes to learn it. It work with any format except vinyl. I used it to help learn to play guitar decades ago. There are better explanations on the website and YouTube. There are similar apps, some free, but in my circles the Amazing Slowdowner is the gold standard. Hope this helps.