Taylor Swift brought on the heat at her weekend concerts in Phoenix, Ariz. by adding a few surprise covers to her set: pop-rock band Jimmy Eat World's 'The Middle,' pop (and sometimes country) singer Michelle Branch's 'All You Wanted' and pop-R&B crooner Jordin Sparks' 'No Parade.' For her take on the singalong anthem 'The Middle' -- seen in the video below -- Swift was joined by Jimmy Eat World's lead singer, Jim Adkins.

"@JimmyEatWorld!!! Thank you to Jim Adkins for rocking 'The Middle' with us in Phoenix!!! I'm such a huge fan, that was unbelievable," Swift excitedly tweeted after the show.

Swift has been paying homage to artists who are based out of her tour stops with countless live covers on the road this year. 'The Middle' seems a particularly fitting song choice for the 21-year-old star. "Hey, you know they're all the same / You know you're doing better on your own, so don't buy in / Live right now, yeah, just be yourself / It doesn't matter if it's good enough for someone else," Swift -- taking lead on the song's second verse -- sings, which could be applied to the fact that she's currently content being single and doing her own thing musically, despite what any 'Mean' naysayers may say. The chorus then comes: "It just takes some time / Little girl, you're in the middle of the ride / Everything, everything will be just fine / Everything, everything will be all right, all right."

"This is someone who's written songs that have gotten me through some of the toughest moments of my life," Swift confessed onstage as she introduced Jimmy Eat World's Adkins.

The audio of the fan-shot video is terrible, to say the least, but viewers can get an idea of what the collaboration sounded like. The 'Sparks Fly' singer also sang Michelle Branch's single 'All You Wanted' onstage on the same night, which can also be watched below. The night before, she covered Jordin Sparks' 'No Parade.'

Watch Taylor Swift and Jimmy Eat World's Jim Adkins Sing 'The Middle' Live

Watch Taylor Swift Cover Michelle Branch's 'All You Wanted'