[em3rgent0rdr]

I get very frustrated with cats on the stage who rely too much on the iReal Pro. If they don't know the melody, then they easily get lost when, for instance, an intro or other section is skipped (such as when the singer re-enters on the bridge after solos), and in general their comping tends to not be aware of how the melody fits in with the changes. At least when reading a leadsheet, readers know how the melody and harmony interact and can better play fills around the melody.

[analog31]

Indeed it's worth mentioning, to a general audience, that iRealPro only displays the harmonies (chord changes) for tunes, and not melodies. Whereas, "fake books" include both melody and harmony.

The reason is that copyright only covers melody and lyrics, not harmony. So the harmonies are essentially public domain.