Recording piano and voice?

Well I dont know exactly what your situation is but if you have a Cascam then you should be able to record then playback and record on a second track,but if you are doing your music with a computer then you could record the piano then save it to your computer and then listen to it and record yourselfe singing,if you don't already have a song then I sudggest playing around with chords(slashed,alterations,and substitutes).