Acts he has worked with include Loose Ends, Phyllis Hyman, Five Star, Stephanie Mills and Regina Belle.

In 1977, Motown rewarded Nick's diligence by giving him additional responsibilities handling dance promotion for the Northeast region covering the territory from New York to Washington.

Although Martinelli and WMOT did well in America with Frankie Smith's "Double Dutch Bus," it took a trip overseas for him to create a niche with his production style; he produced "Act Like You Know" and co-produced "Zoom" for Fat Larry's Band, and it rose to the top of the British pop singles chart in 1982.

Martinelli is perhaps best known for working with the successful English R&B band Loose Ends during the mid-1980s when he produced two of their all-time biggest-selling albums, So Where Are You?

included Loose Ends' biggest hit to date, "Hangin' on a String (Contemplating)," which reached number one on the Billboard Hot R&B/Hip-Hop Songs chart.

In 1993, Martinelli relocated to Los Angeles, where he wrote and produced songs for Jomanda, Regina Belle, Robin S., Howard Hewett, Gerald Alston, Lulu, RuPaul, Chaka Khan, Chris Walker, and his lifelong idol Diana Ross.

In early 1995, Martinelli was called back to London to produce the original cast album for the hit musical Mama, I Want to Sing!, starring Chaka Khan.