Bob Boilen will take the RPM Challenge. Will you? Bob Boilen for NPR hide caption toggle caption Bob Boilen for NPR All Songs Considered Brave And Procrastinating Musicians Wanted January 31, 2011 February 1 marks the beginning of the RPM Challenge. It's the annual invitation to "record an album in 28 days, just because you can." Your finished album should be at least 35 minutes long and composed of all-new material.