To accompany a SONG, the piano has to be discreet. In an ensemble, like our old Schiehallion band, it's very useful, if not indispensable. It is a percussion instrument, and for dancing helps the beat (bass, drums, e.g.). I like to think the way I played, sometimes taking the melody, sometimes playing a counter-tune, or even just running arpeggios up and down, varied the sound appropriately. To accompany a rouser of a chorus song, it's pretty good I'd say. But it's true that as the sole accompaniment of a folk song it can intrude terribly.