The musicians were among the six YouTube stars who performed at the Isle Of Wight Festival 2015 in Newport.
Speaking to the IBTimes UK's A-List backstage at the festival about their success, Trigwell, 24, said: "[It's] amazing. It's nice to say you've performed alongside other YouTubers as well.
"It's not often you can say you've shared the stage with someone else who you've seen had a huge video."
Watch Noah Guthrie cover Sam Smith's Stay With Me:
The self-taught guitarist started her music career at the age of 17 by busking on the streets of Leeds, before taking her talents to YouTube.
With more than 330,000 subscribers, Trigwell has clearly amassed a devoted following.
Addressing the phenomenon of YouTube, which is seeing an increasing amount of vloggers turning their videos into a lucrative income, Trigwell explained: "I think it's just becoming the power of the people [and] it's people that buy your music, not a company.
"Eventually you have to listen to the people and if someone like Zoella who's got eight million subscribers, eight million people following her, you can't ignore that."
Watch Hannah Trigwell perform The Ocean:
US singer Guthrie added: "The industry itself is changing so much that everything is shifted to instant content."
The 21 year old, who clocked up more than 72 million views by singing covers of popular songs, has proved to be such a hit that he even attracted the attention of TV producer, earning him a recurring role in the final season of Glee.
Explaining the root of his success, Guthrie added: "The industry itself is changing so much that everything is shifted to instant content."