By Robin Deits

This puzzle consists of an image of a record. A track listing is given on the record, but only the artists are provided, which suggests that the solver ought to be looking for the song titles. Since this is, in fact, a record, the only thing to do is to try to play it. Playing the record involves sampling the image itself in a spiral pattern, from out to in, just as a real record needle would. In order to do this, solvers need to figure out a few things:

  • The spacing of the record grooves: This can be determined by visual inspection or by guessing and checking. It turns out to be 15 pixels.
  • An appropriate sample rate (in samples per second): Any reasonable audio sample rate from 8kHz to 40kHz will work fine.
  • The record’s turn rate (in RPM): This is given in the puzzle title as 33 RPM.

With this information, it’s possible to write code to play the record, similar to this Python code.

The tracks on the record can be identified as songs by the artists provided on the record:

  • “Revolution #9”
  • “Hard Times”
  • “Hymn 43”
  • “Good Times”
  • “When I’m 64”
  • “Glad All Over”
  • “Days of 49”

Taken together, sections of the titles give a mathematical formula: “9 times 43 times 64 over 49”

The result of the formula is approximately 505.5. This is not the answer to the puzzle. Instead, it’s a hint to repeat the mechanic (with the word “Revolution” in the first song title as a further hint that this has something to do with revolutions). Playing the record back at 505.5 RPM reveals that there is an additional track layered on top of the record, but at a much higher speed:

The fast track can be identified as “Woodstock” by Joni Mitchell. Thus, WOODSTOCK is the answer to the puzzle.