Free, which was dropped on Kirim's Soundcloud page one week prior to the semifinals, is his first release after a year spent refining his new sound.
"It was great to see how many people had already learned the words and were getting amongst when I performed," Kirim said.
"I was up last so I had to keep my calm while everyone around me was letting their hair back and cutting loose.
"By the time I was up there the crowd was at peak, which enhances the whole experience because the crowd already has so much energy to feed you.
"All you have to do is reciprocate that energy. "
He said having the chance to work with Neely was an incredible opportunity.
"I'm not saying we'll be signed, but the networking opportunities and professional advice that could come from such a win alone would be a huge benefit for any artist.
"Especially for a New Zealand artist; this is a completely unexplored channel for us.
"It's also been a great opportunity for artists who haven't been exposed to a high degree of professionalism, to sharpen up on their management and inter-personal skills."
According to Ants, finalists were selected because of good quality and relevant music, stage presence, crowd interaction and professionalism, knowledge of how to market themselves, and an established fan base.
"Def Jam isn't looking for an act to nurture; you need to show them that you're ready to go."
The biggest lesson he had taken away from the experience so far was to be surrounded by a good team.
"I couldn't have achieved any of this without the people I'm working with today," Kirim said.
"I think you need a team who you can trust wholeheartedly, who can reciprocate your focus and ultimately kick back and have a laugh with at the end of the day."
Neely, who was watching the process unfold from America, instigated the event after advice from his good friend and Wellingtonian, Martha Samasoni, the event's lead organiser.
"Martha insisted I come to New Zealand to bridge the gap between the USA and New Zealand to make music a universal platform," Neely said.
"Never before has an A&R from Def Jam in the US come from around the world to find untapped talent."
He said the finalists for Saturday's event were all winners in his books.
"They've obtained the chance to perform in front of me.
"I'll decide on the night if there are any artists I wish to work with hand-in-hand as far as marketing and promotions that can be sold around the world."
He said whether or not the winning act has the full package, in the industry nothing is ever guaranteed.
"We can only open the door (and) it's up to the artist or act to go through it."
Having entrusted local judges to screen the talent around New Zealand as part of the Def Jam NZ Showcase, Neely had been watching video footage of Kirim's performances.
"I see that he has potential," he said.
Download the track Free for free through Kirim's Soundcloud page.
