The Mellotron Group

I've been enjoying Mike's Satie recordings.  Nicely done Mike.  It put
me in the mood for some Debussy.  I have a Debussy sheet music book. 
I found a tune in it called Jimbo's Lullaby that looked easy.  When I
played it, I heard Manfred Mann's Earth the Circle (from Solar Fire).
 The melody is exactly the same.  I don't really want to go digging
around for that LP, but I seem to recall Mann credited as the songwriter.