In the bad old days before the internet & streaming😀, what pieces of music did you have to purchase on a 45rpm single because there was no other genuine way of getting them home? The trouble was that more often than not, an album cut of a rock-and-roll hit would be a different version/take/mix of the one you loved hearing on the radio. Which means you just had to get the 45.
Here's a random handful of mine --
Hanky Panky -- Tommy James & the Shondells
Save the Country -- Laura Nyro
She Don't Care about Time and Change is Now -- The Byrds
Baby Please Don't Go -- Them
Candy Girl -- Four Seasons
The Battle of New Orleans -- Johnny Horton