Kate Molleson heads down to Covent Garden where rehearsals are under way for a new production of Beethoven's Fidelio at the Royal Opera House. She speaks to conductor Sir Antonio Pappano, director Tobias Kratzer and soprano Amanda Forsythe, who sings Marzelline. Fidelio is sometimes considered a problem opera, with its mix of comic and serious, but Kratzer emphasises the deep themes of political revolution and unjust imprisonment, while for Pappano, Beethoven's score opened a new world for German opera, not least for Wagner. Kate also talks to Marta Gardolinska, Young Conductor in Association at the Bournemouth Symphony Orchestra, about the challenges of forging a career as a conductor, and about her love of Polish music. And Music Matters joins the composer Valgeir Sigurdsson and director Stewart Laing as they discuss We Are In Time, a new music-theatre piece for the Scottish Ensemble about a heart transplant. It's a profound exploration of the emotional and scientific aspects of this most risky operation, with the ensemble's string players also taking on dramatic roles and singing. Kate also investigates the effectiveness of mood-based music playlists, with James Foley from Spotify and Hugo Shirley from classical streaming site Idagio - and gets a concert programmer's point of view from Helen Wallace, programme director of King's Place in London. Are mood lists a gateway to the treasures of classical music, or just dumbing down the art form?