Yamaha 303 GM keyboard with 5 pin din midi in/out connected to PC via MIDI/USB cable. Play keyboard no problem with headphones connected to keyboard. Run Sibelius 7. Can hear Sibelius 7 with headphones connected to computer, can input notes via mouse, pc keyboard. I have been able to input notes via the Yamaha gm keyboard and Sibelius will score the notes, however, I cannot hear the notes going into Sibleius with the headphones connected to the computer, unlike my USB Evolution 49's which I can hear the notes played on the keyboard going into the score on Sibelius. So if I play the Yamaha gm keyboard with the metronome keeping time in Sibelius, I cannot hear what I am playing if my headphones are connected to the computer. Has anyone solved this problem? I have very little time to get back to the ICT dept who are looking into new PC's/Mac's and unless I can solve this I am going to miss out on new ones. I cannot have evolutions on every computer!