The song hinted at by the puzzle is Song 2. The phrase Whoo-Hooo! (spelled differently according to some lyric sites) is sung many times during the song.
The song is by Britpop combatant Blur (14A), who have an (ongoing!?) feud with fellow ‘90’s lad culture idols Oasis. One of Blur’s biggest hits was Tender (27A), a song about lead singer Damon Albarn’s break up with Justine Frischmann, lead singer of another Britpop band, Elastica.
Although Blur is still a going concern, Albarn’s main project these days is the “band” Gorillaz (30A, almost). Gorillaz consists of four cartoons animated to play Albarn’s songs, with a rotating cast of terrestrial bandmates.
The answers, explained:
1A – Edna Mode – Edna (Dane extravagant, or anagrammed) + Mode (style). Edna Mode was a fashion designer who created the Parr family’s superhero costumes in The Incredibles and The Incredibles 2. She did not believe in capes.
5A – X Files – File (alien, or anagrammed life), with XS (the tiniest bit) on each side (edgy). Fox program has two meanings – X Files was on Fox, and one of the lead characters was Fox Mulder.
9A – Reprieve – Rep (congresswoman, left, as in, all the way to the left) + RI (Rhode Island) + eve (the night before)
10A – Tangle – t (that premiere) + angle (crook)
12A – Kaiser bun – “A bike runs” haphazardly, or anagrammed
13A – Hatch – double definition (concoct and an escape route)
14A – Blur – the edges of BLack sulphUR
16A – Swanson – Swan song, without the last piece, or letter. Nick Offerman played the libertarian Ron Swanson on Parks and Recreation, who had both a heart and a secret cache of gold.
19A – Learned – lear (Shakespearean king) + ned (calamitous, or anagrammed end)
21A – Woke – We with OK (approve) inclusive
24A – Fetch – Fletch (Chevy Chase’s title role) undefeated – no L (loss). Chase played detective Irwin M. “Fletch” Fletcher in two movies, Fletch and Fletch Lives. As is common with Chevy Chase’s oeuvre, only one of these movies was very funny. So on second thought, let’s not bring him back.
25A – Strapless – Staples (pantry essentials) + r (a smidge of rice) + s (a teeny bit of sauce)
27A – Tender – double definition (weak and currency)
28A – Tenspeed – Tens (hotties, i.e., those who score a 10 on a 1-10 scale of attractiveness) + peed (went to the bathroom)
29A – DeSoto – “Does not” on a journey, or anagrammed without the letter n (neutral)
30A – Gorillas– contained in nettinG OR ILL ASsume
1D – Eureka – You + reek (stink) + uh in a resounding way, or heard. Eureka, the state motto of California, means “I have found.”
2D – Napkin – Nap (siesta) + kin (brothers and sisters)
3D – Maize – I (this guy) surrounded by maze (a series of twists and turns)
4D – Dive bar – “I braved” recklessly, or anagrammed.
6D – Flashback – Flack (publicist) standing outside + ashb (wild, or anagrammed bash)
7D – Lightest – lie (falsehood) + test (detector), speech based, or heard
8D – Seething – confused, or anagrammed, “teen sigh”
11D – Inns – The first letters of I Need New Suggestions
15D – Lunchmeat– L (to begin with 50) + unchm (munch top to bottom) + devour. Use of the word “whatnot” is in tribute to/stolen from the great comedian George Wallace.
17D – Illfated – ill (dope) + fat (overweight) + ed (horse, as in Mr. Ed)
18D – Martinis – Martin (as in Dean, Jerry Lewis’s old partner) + is
20D – Dash – double definition (a little and speed)
21D – War hero – War (vulnerable, or raw, regressive & first) + her + o (love)
22D – Reveal – rev (put the pedal to the metal) + eal (a ton of zeal)
23D – BSides – besides (as well as) heard
26D – Pesci – contained in (with) escaPE SCIntillation. In Goodfellas, Joe Pesci played psychotic gangster Tommy DeVito, who pretended to be offended when told he was funny, asking “I’m funny how, I mean funny like I’m a clown, I amuse you?”