iHeartRadio Fest Saturday: Lady Gaga, Kenny Chesney Own Sin City

iHeartRadio Music Festival

Lady Gaga performs at day 2 of the iHeartRadio Music Fesitval at the MGM Grand in Las Vegas.

Night two of the the iHeartRadio Music Festival played out far different than the first night. On Saturday (Sept. 24), the bill at the MGM Grand in Las Vegas was filled with acts that are more genre specific than on the previous night, and most of them were more interested in presenting their hits in compact 20-minute sets than spreading the love to radio programmers and their fellow artists.

As the de facto headliners, Kenny Chesney and Lady Gaga provided a unique contrast in styles. Some of their differences are obvious -- Chesney presented country influenced by early '90s hard rock, while Gaga gave the crowd dance-pop influenced by everything from Elton John to Madonna to country. However, it was the approach of the performers -- the ultimate insider vs. the ultimate outsider -- that distinguished them from one another.

PHOTOS: iHeartRadio Music Festival

Chesney sees music as a bond built around good times, a way to get to the heart of all the shared memories about beer drinking and beach parties. Gaga comes from the other side -- music as a rescue team, capable of pulling the abused and unwanted out of negative situations. Gaga's 50-minute set trumped Chesney's half-hour plus in emotional layering, but as a soundtrack to a backyard party, Chesney comes out ahead.

iHeartRadio Fest Friday: Jay-Z, Alicia Keys, Coldplay Bring the Heat to Vegas

As contemporary as the night was -- a half-dozen songs performed are on this week's Billboard Hot 100 -- there was a definite nostalgia component at play. Gaga and Sting swapped verses on the Ben E. King, Jerry Lieber and Mike Stoller hit "Stand By Me," Steven Tyler and Jeff Beck connected with 60s Brit rock and 70s Oakland funk, and the revamped Sublime with Rome resuscitated late-90s ska-punk classics.

Here's a rundown of all of Saturday's iHeartRadio Music Festival performances, in order of appearance:

Steven Tyler and Jeff Beck
Set highlights: With Beck's bassist Tal Wilkenfield in tow, they proved their mettle on '60s riff rock (the Kinks' "You Really Got Me") and funk, (Sly and the Family Stone's "Thank You (Falettinme Be Mice Elf Agin)"). Tyler's voice was as expansive as Beck's guitar work, and they succeeded on the gimmicky menage a judge with bassist Randy Jackson and singer Nicole Scherzinger on "(It) Fee;ls So Good."

Nicki Minaj
Set highlights: After Tyler and Beck, Minaj proved herself to be the flipside of nostalgic with a set that was very in-the-moment. Performing "Why You Mad" that she recorded with Birdman and "Where Them Girls At" with David Guetta, Minaj's set also included "Can't Stop, Won't Stop," "Moment 4 Life" and, of course, "Super Bass." Meanwhile, her dancers impressively played everything from nurses to school girls to can-can dancers.

Rascal Flatts
Set highlights: Bringing out Natasha Bedingfield to sing their current release "Easy" took the audience's eyes off the Flatts' outdated ensembles of white pants and embroidered black shirts. Meanwhile, "Fast Cars and Freedom" still sounds fresh six years after its release.

Video: Rascal Flatts Invade iHeartRadio Fest with Natasha Bedingfield

Jennifer Lopez
Set highlight: Lopez delivered a varied performance that connected with songs from throughout her career and felt honest. "Get Right" from 2005's "Rebirth" was a quirky choice for the lead-off number, but it segued nicely into "Let's Get Loud."

Video: Jennifer Lopez Talks New 'Idol' Season at iHeartRadio Fest

Sublime with Rome
Set highlight: Rome is no Bradley Nowell, so hearing a different voice on "What I Got" will result in charges of sacrilege and shrugs of the shoulder, depending on the listener. Out of place in this lineup, the Long Beach, Calif.'s ska-reggae-punk is oddly tepid and unmoving, whether it be on the new "Panic" or a classic like "Santeria."

David Guetta
Set highlight: At the end of his dance set, which featured giant battling robots and remixes of "It's No Getting Over You," "Little Bad Girl" and "When Loves Takes Over," Usher stepped out to croon "Without You." Guetta proved that a smiling DJ clapping his hands can be just as well received as a rock band, and acknowledged that he was "emotional" over the fact that dance music has been accepted in the U.S.

Kenny Chesney
Set highlights:" I Go Back" and "Living in Fast Forward" stood out among the high-powered set of seven songs.

Lady Gaga
Set highlights: A duet with Sting on "King of Pain," show closer "The Edge of Glory" and the emotional ballad "Hair," dedicated to 14-year-old suicide victim Jamey Rodemeyer, were part of the broad palette Gaga employed. Souped-up motorcycles in a vintage sign graveyard provided Gaga with gritty surroundings; she smeared "blood" on exposed skin to physically render "pain," which felt like one step too far.