Mumford & Sons bring out 'Boston' hitmaker Stella Lefty to perform live at their Madison Square Garden show.

Lefty chose to celebrate her 24th birthday by meeting up with folk band Mumford & Sons to continue their performance kinship together. The 'Boston' songstress featured as the band's surprise guest, playing the third night for the groups MSG dates on their Prizefighter tour run.

"MSG, I like it when you're nice to me" the band cleverly tied in the hook of the song as the caption of their latest social media post, which featured a short clip of Lefty and the group's lead singer Marcus Mumford playing her hit together.

An exciting night for their New York City crowd, as fans got to experience the artists teaming up again for the first time since their Hyde Park concert back in early July.

After 16 songs out of the group's 25 song setlist were played, featuring hits like 'Little Lion Man' and 'Begin Again,' Mumford strung the first few chords of Lefty's hit and sang the opening line, when fans immediately recognized the chart soarer and grew ecstatic at the potential for a cover. Excitement grew when Lefty casually walked on stage, taking control of the first verse and preparing to perform alongside him.

'Boston' wasn't the only song the artists got to play together, however. Lefty also accompanied the band with their song 'Here' off of their Prizefighter album, which originally holds a powerful Chris Stapleton feature.

Surely a memorable birthday celebration for Lefty, and an exciting collaboration for Mumford & Sons, the group's chemistry with the rising star is nothing short of electric. Lefty's country roots, with an aptness to bridge the gap into pop and folk, meshes amazingly with the band's folk roots.

Both artists hold a deep appreciation for unwavering emotion and vulnerability in their music, making their performances together a safe space for both to lay it all out on the table - as they blend both the passions for their songs and genuine love for performing whenever they are paired together.

Lefty's surprise performance with Mumford & Sons also took place about a week out from her August 21st release of her debut album Long Way Home, which is set to feature songs such as 'lean in, kiss me' from the artist.

While we're not sure what collaborations Lefty has up her sleeve for the new record, if any at all, one thing we can bet on is a continuance of her relationship with Mumford & Sons, and with any luck, a song displaying their chemistry together in full studio mode in the near future.