The conductor as a wanna be composer

I know Beecham is said to have composed, though I've never heard anything. There's a nice if forgettable piece by Norman Del Mar on a Dutton release. And a piece by Barbirolli was recently released somewhere. I suppose that sometimes it was useful for conductors to get a feel for what it's like to write music, even if they have no great ambitions. I would say my favourite "conductor-composed" piece must be Henry J Wood's Fantasia on British Sea Songs.