[1] He has worked with over 40 acts including AC/DC, Aerosmith, Black Sabbath, Emerson, Lake & Palmer, Foreigner, INXS, Iron Maiden, Judas Priest, Meat Loaf, Mötley Crüe, The Rolling Stones, Ronnie James Dio, David Lee Roth, Scorpions,[2] and Rod Stewart.

The tribute concert, which took place at Wembley Stadium for an audience of 72,000, featured a wide variety of guests including Robert Plant (of Led Zeppelin), Roger Daltrey (of The Who), Extreme, Elton John, Metallica, David Bowie, Annie Lennox, Tony Iommi (of Black Sabbath), Guns N' Roses, Elizabeth Taylor, George Michael, Def Leppard, Seal and Liza Minnelli.

[7] In 2002, he traveled with the Scorpions, working together with the German lighting designer Lars Wulff, on the most extensive rock & roll tour of the old Soviet Union ever undertaken at the time.

Prior to becoming a lighting designer, Cosmo worked as a backline technician for such bands as Joan Jett and the Blackhearts, Mink DeVille, D.L.

Byron and Falcon Eddy, and musicians such as Ricky Byrd, Willy DeVille, Joan Jett, Thommy Price, Robert Sarzo and Johnny Thunders.