The music of In the Groove includes 136 songs for arcade and home releases.
An easier Novice difficulty offers charts at level 1 for all songs in both games.
Note the numbers given for each difficulty level are similar to DDR's 1-10 "footers", except In The Groove removed the "footer" label and added 3 additional difficulty levels, which aim to have harder stepcharts than the hardest 10-footer songs in DDR.
Ward (which include ones by his stage names Smiley (☺), Inspector K, Kbit, and Banzai) can be found on his studio album Synthsations which is available for digital download.
The home version was only released on PC and Mac, and requires the installation of Song Pack A.