The idea was to have three songs that somehow deal with April fools, but I could only think of one.
(mp3) Fair To Midland - April fools and eggmen
Available on Fables from a Mayfly: What I Tell You Three Times Is True (2007)
(mp3) MonstrO - April
Available on S/t (2011)
(mp3) Opeth - April ethereal
Available on In Live Concert at the Royal Albert Hall (2010)