[5] Working in studios across Europe and the United States, Manahan has written and / or produced tracks for a diverse range of international artists including Liberty X, HotCha,[6] Willy Denzey, J-Son and Christina Aguilera.
In June 2011, Manahan spent several days in the studio with artist Adam Lambert, recording, writing and producing "By the Rules", which features on the deluxe edition of Trespassing.
In August 2011, Manahan spent time in the studio in London with artist Pixie Lott, recording and producing new material.
[10] On 2 September 2016, UK artist Rebecca Ferguson released her cover of "Bones" as the debut single from her fourth studio album Superwoman.
[11][12] In 2014, Manahan co-produced the studio version of "Holding You", Blackmore's collaboration with fellow Kiwi artist Stan Walker, which also reached the top of the NZ chart.