Little boy blues - seed of love (i'm not 100 % sure if that's the correct band name, but you should find it anyway when you search for the title). But I think Jay-Zs version was replayed. In the original sample, the low end seems to be played by a trumpet or trombone or something, but in PSA it seems to be a piano. The organ is also a little louder on PSA than the original sample. Btw the same sample was also used in Black Moon - Stay real.