The whole song, Matt. It used to work that if you pressed EXPAND while the song was playing without changing tempo, 2 bars of B flat would just turn into 4. But if you did it with the song stopped, a 100 tempo would become 200.

Now....the tempo doubles regardless. It's a feature I've always use daily-especially on long form songs like End of a Love Affair, The Song is You, or Cherokee. Depending on tempo, you may want to halve or double the chord time. And while EXPAND or REDUCE while the song was playing USED TO make the change without altering tempo....now it ALWAYS halves or doubles it.