Johann Adolph Hasse’s Siroe (Dresden, 1763) was a setting of Metastasio’s hit libretto about an otherwise utterly unmemorable King of Persia. Kavadh II was king of the Sasanian Empire for all of one year in 628 after revolting and overthrowing his father. Vinci, Vivaldi and Handel all had a stab at it, and Hasse’s original version starred Farinelli and Caffarelli, but what we have here is his later reworking of the opera.

It’s one of those ‘make-you-want-to-shout-at-them’ plots. It seems everybody except his son Siroe is plotting against tyrannical King Cosroe, but who is it that the silly old sod suspects? Yes, you’ve guessed it – Siroe. And, of course, the latter is the only person so honourable that he prefers to stay schtum rather than betray the others.

Hasse reveals himself a master of baroque form, perhaps lacking Handel’s memorability, but his equal in structural sonics and dramatic ambition. Occasionally he makes a musical wrong call – an over-passive aria might follow a recitative that should imply a number with a bit more musical spunk – and the modern restorers have had recourse to a couple of inserts from other works in the final act to help things along.

Lively orchestral...