I mainly sing unaccompanied and am able to change the decoration, empasis and timings as I feel fit. Its quite a challenge to sing with accompaniment.   I find that quite often it slows the song down as I am letting the other instruments fill the gaps in the song.   This is not necessarily a bad thing but there are times when you loose the power of the ornamentation and the flow when you have a rthymn forced on you.

J