Actually,Marcellin is right, there were no Byrds. It was just another elaborate practical joke perpetrated by John Lennon. He and McCartney had just had a hit called Michelle under the pseudonym David and Jonathan, and thought it would "shove a sapling up the Queen's knickers" to write and perform music as an "American" pop group. This was right before Paul died and was replaced by a 23 year old milkman from Wrexham.

There was also no Pete Seeger, but that's another story...