Prefer it to apple’s default Music app
This app accesses the songs loaded into apple’s Music library or you can put the songs into this apps folder via your computer. It allows more customisation of all frequencies from bass through to treble using a graphic equalizer compared to apple’s Music app’s set presets. You can use THIS apps presets or save your own & it’s also possible to increase the volume level beyond what apple’s Music app will allow, which is useful if you have the odd album that seems to have been recorded at a much lower volume level compared to your other albums.