The group bonded with the One Direction singer after he went to one of their gigs, and they spent an interesting day in the recording studio together afterwards, though singer Steve Garrigan has no idea what the 'Little Things' hitmaker wants to do with the tracks.
Asked if he thinks Harry will go solo, Steve told BANG Showbiz: ''I have no idea if that's the plan at all. But writing with him was very cool.
''He came to one of our shows and we were just hanging out afterwards. We all had the next day off so decided to go to the studio together and played music together all day, that was how it all came about really.''
The 'High Hopes' group have performed a string of recent outdoor gigs including at the Glastonbury festival and the Summer Series at London's Somerset House with American Express, and love the differing experiences they get for playing different sized crowds.
Steve explained: ''Glastonbury was amazing and at the time was definitely a career highlight.
''Large gigs are always great because of the sheer volume of the crowd, but small, intimate gigs, like the Summer Series, are equally as exciting for a musician.
''When you perform you feed off the energy of those listening and obviously being able to attract a big crowd and entertain them is great. But on the flip slide, a smaller crowd is slightly more personal.''
Kodaline were part of the stellar line-up for this year's Summer Series at Somerset House with American Express(r), just one example of the enriched entertainment experiences available to Cardmembers.
For more insider information from some of the UK's most sought after events visit youtube.com/AmericanExpressUK.