Where do I begin is RTÉ Arena's popular weekly slot where they demystify the back catalogs of some of film, music and literature's most prolific and respected artists.

This week, it's the turn of composer extraordinaire Stephen Sondheim - the couturier and fashion designer, Peter O’Brien joins Seán in studio to talk all things Sondheim, and share his own favourites. 

Tune into to RTÉ Arena live nightly from Mon-Fri on RTÉ Radio 1 from 7pm - or listen back here.