I used the drywhite sample provided on the m220a homework page, and combined it with data from average monthly temperatures across the world between 1701 and 2011 from the Teniente B./Matienyo, Vostok and Ascension Islands weather stations. The rhythm of the bassline is coded in the chuck files and not retrieved from data. The pitch of the bassline is based on data from harmonised unemployment rates "over 25 years" of the United Kingdom.
The data files for reading in chuck can be downloaded here: