VHM to "Mmm Mmm Mmm Mmm," one of only two charting hits to have only one unique letter in its title. (The other was a recent hit no one here would know: Omarion, "O.")
I've mentioned in times past the peculiarity of ABBA's "SOS" being the only charter in which both the artist and song title are palindromes. But this week's Billboard Dance/Club Play No. 1 hit is the first case of artist PLUS song being a palindrome: Ono (as in Yoko), "No No No."