As they make reference to a song released in 1971. (That's 37 years ago if my math is right.)
On a very unrelated note, I was in line to pay my entry fee a couple of Saturdays ago for the half marathon in downtown Fort Worth when I dropped four $20 bills on the ground in a crowd. I heard lots of "woahs" as I scrambled to pick them up. I then sheepishly said, "I was just trying to make it rain out here." One guy laughed. The other sounds were crickets chirping.