Control playback and get around the Spotify desktop app without reaching for the mouse.
The point of Spotify's shortcuts is to manage your music without switching away from whatever you're actually doing. Space plays and pauses, ⌘/Ctrl + → and ← skip to the next and previous track, and ⌘/Ctrl + ↑/↓ nudge the volume. Once these are in your fingers, you rarely need to bring the Spotify window forward at all.
The other big time-saver is search. ⌘/Ctrl + L jumps straight to the search box so you can pull up a song, album or playlist in a couple of keystrokes, and ⌘/Ctrl + R toggles repeat while ⌘/Ctrl + S toggles shuffle. Together these cover the handful of actions you reach for most during a listening session.
One thing to know: these work in the desktop app, and the web player supports a slightly different, smaller set. System-wide media keys on your keyboard (the play/pause and skip buttons) also control Spotify even when it's in the background, which pairs nicely with the in-app shortcuts. For controlling everything else by keyboard, the Mac and Windows cheatsheets cover the system itself.