Why not just speed it up
Playing a song faster raises its pitch with it: about 6% faster is one semitone higher. That's fine for a small nudge in a DJ mix, and useless when the song has to stay at its tempo.
Move the key, keep the tempo
These steps use DropWave Editor, a plugin for Mac (AU, VST3 and CLAP, free during the beta).
- Put DropWave Editor on the song's track and let it hear the song once: Capture, play, stop. It reads the key, tempo and tuning and splits the song into stems.
- Open Pitch. The song's key is shown on the Camelot wheel.
- Click another key. The song moves there, live, at the same tempo, and the wheel shows what mixes with where it landed.
Turn on Keep formants to keep a voice sounding like itself as its pitch moves. Compare plays the song as it came in, in time, so you can hear the difference.
Fix the tuning while you're there
Fix tuning brings the whole song to A = 440 Hz, or to 442, 444 or 432 Hz, so a sample or a record that's a few cents off sits with everything else in your project.
When it's useful
- A sample in the wrong key for your project, moved to yours.
- A DJ edit moved one step around the Camelot wheel to mix into the next track.
- A song for a singer, moved into their range.