Transpose a song from inside a playlist and that key is remembered for that playlist alone. The same song can sit in one playlist in F and in another in its original key.

 

This is a soft transposition, so the chart itself is unchanged. To change the key the chords are actually written in, use a hard transposition in the Editor: see Transpose a song.

 

For more, see Organize your songs into playlists on the iReal Pro website.