Real time recording by Digital piano

Bomi

<Symphony for iphone>

When input notes by 'Real time recording (use MIDI, digital piano)

how to select to 2 staves at a time? (ex. Piano's upper stave & lower stave) 

I know the way, <Symphony Pro for IPad>

But the way doesn't work on <Symphony for iphone>

Please let me know. Thank you.