There's nothing better for me than a session mixed with tunes, unaccompanied and accompanied song! Sadly it seems that ne'er the twain shall meet. Accompanied & unaccompanied singing appears to be an accepted mix in a singaround but to try & put a voice into a music session where the only remit often seems to be the faster the tune (& sod the quality) the better is usually impossible. As soon as one tune finishes another musician will noodle straight in with another tune...no gap for anyone to start song (but remember that our voice is an instrument too).