The song hinted at by the puzzle is The Magic Number, by De La Soul, a HIP HOP (28A) group from Long Island, NYC, part of the Native Tongues Posse that began in the late 1980βs/early 1990βs. De La Soul is my absolute favorite hip hop group, and the source of my twitter name, delajeff, which was my original AOL email address. One thing that rappers and crossword solvers have in common is a love of wordplay, and De La Soul is no exception. The act consists of three members: Kelvin Mercer is Posdnuos, βsounds opβ backwards; Vincent Lamont Mason Jr., aka βMaseo,β and David Jude Jolicoeur, who goes by βTrugoy the Dove.β He picked the name because he loves YOGURT (22A).
The Magic Number is the lead song on the groupβs first album, Three Feet High and Rising, which featured the single POTHOLEs (4D) in My Lawn. The entire album is extremely sample heavy, which has led to a host of legal problems and kept this masterpiece of an album off of streaming services. The Magic Number borrows many elements from the song Three is a Magic Number, written by Bob Dorough for SCHOOL (11A) HOUSE (31A) ROCK (10A). The title of this puzzle, What is It, is asked in both songs. As referenced by the album title, the song also samples Johnny Cashβs song Five Feet High and Rising, hence the Cash photo.
BTW, De La Soul are also featured in the song Feel Good Inc. by the Gorillaz, which you can read about in last weekβs answer, or at your local internet cafe. Here’s a version of the song mashed up with Fela Kuti.
The grid:

The answers, explained:
ACROSS
8A β FILM β double definition β grimy part/cinema
9A β ANODE β An anode receives current β A + N (novelistβs opening) + ODE
10A β ROCK β double definition β unnerve/a source of solace. In these two senses, ROCK is a contronym, a word that has opposing meanings.
11A β SCHOOL β SOOL (backed up toilets ) + CH (one third chrome)
12A β HUNGOVER β HUN (brute) + GOVER (monster β Grover, from Sesame Street β without the R (are pronounced, or heard, missing))

13A β SPITBALL β TBA (to be announced) amid SPILL (splash)
15A β TRENDY β TR (early 20th Century President, Teddy Roosevelt) + END (sordid, or anagrammed, den) + Y (Why, for crying out loud, or heard).
17A β FEARFUL β F (some of of) + EARFUL (harangue)
19A β CLUBBED β CLUED (given a warning) about BB (tiny ammunition)
22A – YOGURT β YOUR GUT churned, or anagrammed, removing one of the uβs (unless top layer is removed)
24A β EASTERLY β STE (diminutive, or shortened, French word for martyr, saint) in EARLY (ancient)
26A β SHOWTUNE β NUTS WHO going crazy, or anagrammed + e (beginning of each)
28A β HIP HOP β HIH (first notes of Hot in Herre) and O.P.P. mixed. Hot in Herre is a song by Nelly; O.P.P. is a song by Naughty by Nature that promotes promiscuity, another thing in common between rappers and crossword solvers. (You down with Other People’s Pencils?)

30A β SPUR β double definition β motivate/ Texas sharpshooter, AKA San Antonio Spur
31A β HOUSE β HOE (dig up dirt) surrounding US (our country)
32A β NAIF β the even letters in uNsAtIsFiEd until the end of timE.
DOWN
1D β ZINC β Zin (wine reduction) + C (cheese rind)
2D β IMPOSTER β IM (instant messaging) + POSTER (communicator, i.e. person who posts)
3D β DAHLIA β AIL (lidless bucket, or pail without the p) + HAD (contained) ascending, or running up
4D β POTHOLE β THE POOL strangely enough, or anagrammed
5D β NEONATAL β NEON (inert gas) + AT A + L (laboratoryβs opening)
7D β ACRE β the first letters (starting points) of A Commercial Real Estate
14D β PREGO β GROPE irrationally, or anagrammed
16D β DWELL β D (democracyβs establishment) + WELL (okay). Here in the States, we need to dwell on democracyβs conservation.
18D β UNTRUTHS β captivated, or contained, in aUN TRUTH S pins. What was I saying about conserving democracy?
20D β BEERPONG β EERP (peer confuzzled, or anagrammed) in BONG (hookah)
21D β REVENUE β RE (in connection with) + VENUE (location)
23D β UPWARD β UP (little dog without its head) + WARD (keep away)
25D β SCHLEP β HELPS + C (basic tip) somehow, or anagrammed
27D β HIPS β HS (High school) harnessing IP (intellectual property)
29D β OMIT β the midsection of frOM ITs