I have both a Bb and a Eb instrument (tenor & alto saxes). Sometimes i only have one with me (say, the Bb one) and want to practice in the other instrument's key (the Eb one) ..
So i want to see the Eb version chart and play on the Eb chart, but with my Bb instrument, so i need to lower (or highten?) the pitch of what i am seeing on the screen ..
How do i proceed ??

thanks!
Matt