They All Played Ragtime is a non-fiction book by journalist Rudi Blesh and author Harriet Janis, originally published by Grove Press in 1950.

[1] According to the Preface to the Fourth Edition, by Rudi Blesh, the book was conceived and researched largely by Harriet Janis,[2] who died in 1963.

In a recorded discussion between Rudi Blesh and pianist Milton Kaye, Blesh revealed that for a long time the authors were not able to find out any information about Joseph Lamb, and that some believed the name to be a pseudonym for Scott Joplin.

In it, he states how that edition includes sixteen complete ragtime piano scores, and that Donald Ashwander was the copyist for most of them.

In addition to a new rag by Joseph Lamb, the scores included more recent ragtime compositions by Ashwander, Max Morath, Bob Darch,[6] and Peter Lundberg.