Londoners and London-lovers: please suggest some (non-obvious) cool things in London to do in March. (I’m insisting on lots of time at the British Museum, and on the Mithraeum, and my wife wants the Harry Potter tour). I’ve been there, wife and daughter have not, son is going to school there.
@Popehat find out if there are any concerts at St. Martin's in the Fields (just off Trafalgar Square), and/or a musical service at St. Paul's. I'm not Christian, just interested in music and great acoustics, and both of these spaces are great spots to hear music.
Wilton's Music Hall: derelict pleasure palace gets a ramshackle restoration

Tucked behind a row of terraces, this vast barrel-vaulted venue is the East End’s best-kept secret. Now, thanks to an overhaul that leaves the tattiness intact, a beguiling Tardis of Victoriana is open for business once more

The Guardian
@Plumbert @Popehat St. Martins absolutely, especially "X by candlelight", where X is a well-known classical piece. March 4 is Vivaldi, March 11 Magnificat, and March 24 is Moonlight Sonata. https://www.stmartin-in-the-fields.org/spring/
Spring & Summer Concerts at St Martin's - St Martin-in-the-Fields

St Martin-in-the-Fields