"Glee" broke the rules of television last year when it premiered on Fox and then went on hiatus for four months, letting word-of-mouth momentum build it into a full-fledged smash. Now, in the middle of a four-city tour that includes five shows at Radio City Music Hall this weekend, the cast of "Glee" is reshaping the music industry as well. Here's how:

NONSTOP RELEASES For decades, the music industry has been built around the album. There's a run-up of two or three months, a release, a tour that coincides with (if all works well) a leveling off of sales, followed by the recording of a new album that starts the process over again. Not "Glee."

Since November, the show has released four albums - including "Glee: The Music, the Power of Madonna," which debuted at No. 1 in April, and "Glee: The Music, Vol. 3 Showstoppers," released last week and expected to top the charts this week. The "Glee" cast has already landed 48 singles on Billboard's Hot 100 since June, the fifth-highest total in the chart's history behind The Beatles, The Rolling Stones, The Beach Boys and The Temptations. Maybe this success will convince record companies to try something different.

The show supports the music which supports the show. TV-related concert tours aren't that unusual these days, considering how Disney's "Hannah Montana" and "Camp Rock" franchises have packed arenas with screaming tweens for years. But the timing of the "Glee Live" tour is interesting because it leads up to the season finale and even offers fans a sneak peek at live performances that haven't aired on the show yet, notably the "Faithfully / Any Way You Want It" duet from next month's finale. Word of mouth from that - and "Bad Romance" from this week's Lady Gaga episode - should generate even more buzz for the show.

CHOIRS ARE COOL The success of "Glee" has fed into a revival for choirs that includes the NBC series "The Sing-Off," which featured a capella groups from around the country competing, and Ben Folds' album that compiles university choirs' a cappella takes on his hits.

At a time when so much of the industry is focused on solo singers, the choir resurgence values teamwork and harmony, as well as showcasing the importance of arts education in schools.

The 'Glee' Live set list

advertisement | advertise on newsday

Hopefully, Mr. Schuester won't get as mad about this setlist leak from the tour's West Coast shows.

"Don't Stop Believin' "

"My Life Would Suck Without You"

"Push It"

"Don't Rain on My Parade"

"Beautiful"

"Sweet Caroline"

"The Boy Is Mine"

"The Lady Is a Tramp"

"Defying Gravity"

advertisement | advertise on newsday

"Bust Your Windows"

"Bad Romance"

"Dancing With Myself"

"It's My Life" / "Confessions"

"Halo" / "Walking on Sunshine"

advertisement | advertise on newsday

"Rehab"

"Mercy"

"Jump"

"Faithfully" / "Any Way You Want It"

"Like a Prayer"

"True Colors"

"Somebody to Love"

What the critics say

"In case the wall-to-wall media coverage hadn't already alerted you, television's ugly ducklings have become real-world swans, and Thursday's 70-minute performance had the triumphant, sometimes self-satisfied feel of a victory lap."

- Mikael Wood, Los Angeles Times

"The songs that came across best live were on the wholesome side of the pop divide. The raps and overt sexuality on Salt-N-Pepa's 'Push It' felt a little forced and out of character. . . . But the show's producers obviously know that, which explains the emphasis on Journey over hip-hop."

- Ed Masley, USA Today

"If you've ever wanted to be in an episode of 'Glee,' that's what the concert, which featured an impressive 23 numbers, was like. Each number was pretty much a re-creation of the one from the episode, down to the wardrobe and moving classroom set."

- Vlada Gelman, EW.com

WHAT "Glee Live"

WHEN | WHERE 8 p.m. Friday, 3 and 8 p.m. Saturday and Sunday, Radio City Music Hall, 1260 Avenue of the Americas, Manhattan

INFO $44-$94; 212-247-4777, radiocity.com