From 1984 through 1992, he worked as a circulation representative for the Toronto Sun; Conrad Black heard him singing at company parties.

Black, along with other executives, financed McDermott's independent recording of "Danny Boy" in 1992, which was picked up and released in North America by EMI Music Canada.

He also appeared at several special events including the D-Day ceremonies in France in 1995, and the United States Democratic National Convention in 1996.

He formed The Irish Tenors, and after performing a large concert in Dublin, Ireland in 1998, they spent some time touring the United States, appearing on television, and releasing a gold record.

[citation needed] In 2010, McDermott took part in the World Jazz for Haiti charity album, recorded at Number 9 Audio Group in support of the Red Cross disaster relief fund.