Hoya!
Nonono! Here is the real story:
The band were at the singer's (or guitarist's I do not recall) and he told them he wrote a new cool song.
They asked for the title and since he was a bit plastered, he moaned something which sounded like In-A-Gadda_da_vida.
The song, by Iron Butterfly, is, indeed part of the album with the same name. It is a long tune, almost 20 minutes.
If you love long, progressive music (in the general meaning), try to get Get Ready by Rare Earth (I think it has not been issued on CD), both Sweet Smoke albums (very nice prog Jazz-Rock), ANY Fela Kuti album (his tunes were around 15 minutes each) or Miles Davis' so-called electric albums from the 70's :-)
If you want more info about good music, just ask :-)
Be funky
M A D