Gregory Porter’s series charting great pop singers through the ages centres on crooners this week.

The invention of the electric microphone allowed singing with subtlety to flourish. From Bing Crosby and Nat ‘King’ Cole via Elvis Presley, Marvin Gaye and David Bowie, the crooner can ‘caress with the voice’ – but also crop up in unexpected places, as Iggy Pop, one of many fine contributors here, proves.

Bing Crosby’s daughter Mary, guitar ace Lenny Kaye, singer Beck, producer and Bowie collaborator Tony Visconti and The Wire actor Clarke Peters are among the talking heads in this lovingly curated series.