On 30 September 1947, in his Hollywood recording studios, Duke Ellington and his band (which at the time included jazz luminaries Billy Strayhorn, Johnny Hodges and Oscar Pettiford) knocked out a track which must be a record (no pun intended).
With the help of vocalist Ray Nance, Ellington recorded a tune with, surely, one of the longest words in the Oxford English Dictionary:
You're Just An Old Antidisestablishmentarianismist
And no, Pepsi's strapline from the 1970s Lipsmackinthirstquenchinacetastinmotivatingoodbuzzincooltalkinhighwalkinfastlivinevergivincoolfizzin doesn't count!