This is the song Kirk dances to in his film – Miss Patty did the choreography.
White Lines (Don’t Don’t Do It) is a 1983 song by hip hop artist Mel Melle, written by Melle and Sylvia Robinson, and released as a single. On original release, it was credited to Grandmaster Flash and Melle Mel, but by that stage Flash and Melle had stopped touring together and were in a legal disagreement.
Originally it was an ironic celebration of the cocaine-fulled party lifestyle, but for commercial reasons was abridged with the “don’t do it” message to warn against the dangers of cocaine. It has an unofficial music video directed by Spike Lee and starring Laurence Fishburne. The song went to #9 on the US Hot Dance Club Play charts, but did best in the UK, where it made #7 on the charts.
Lorelai says that Kirk raps in the film (presumably to the song), but we never hear that happen. Kirk also tells Lorelai he needs to keep the word “damn” in his film to maintain his street cred, but we never hear him say that, either.