Probably direct references to:
Martin Scorsese's Raging Bull. Both are films where music and score play an essential part of the narrative, and given Do The Right Thing's themes of Lee's frustration with the fighting between the Blacks and Italians in Bed-Stuy, this homage can be seen as Spike Lee stepping up to Scorsese's level. He's paying his due respects, while also declaring that he is capable of creating something just as good, however different. The fact that Scorsese was and is well-known for showing the "dirty side" of NYC, yet Lee was ready to do the same thing, in a side of the city that hadn't received mainstream representation yet.
Of course, DTRT has plenty of more blatant references:
Then finally, a three years later, another film took a great throwaway line from Spike Lee which also owed a great deal to the films of Scorsese:
Sweet Dick Willy: Shit, Mike Tyson even dream about whoopin' my ass, he better wake up and apologize.
Mr White: Shit, you shoot me in a dream, you better wake up and apologize.
