What I do is connect my iphone to my home entertainment center, fire up iRealBook and play the iphone through my home speakers like I do with Pandora or Sirrius XM.

I print out the charts and keep the iphone near me so I can change tunes, change tempos, and keys. If I need to practice at night, I plug in my headphones into the home entertainment center. Works like a charm :-) iRealBook Rocks!!