Musetti began competitive racing in the 1976 Shellsport International Series, driving for David Price Racing in a March 752 with Ford power. He finished sixth in the standings with 43 points. In 1977 he remained with David Price Racing in the same series, improving to third in the final standings with 85 points. His 1977 campaign included a race victory at Brands Hatch, where he also set pole position and recorded the fastest lap of the race.
Alongside the Shellsport programme, Musetti entered the 1976 European Formula Two Championship under his own entry in a March 74B, scoring no championship points. In 1977 he contested the European F2 season with David Price Racing in a March 742 but again failed to score.
Musetti raced in the British Formula One Championship — the Aurora AFX series — across several seasons. In 1978 he drove a March 752 and March 761 with a Ford Cosworth DFV engine and later switched to an Ensign N177 prepared by Mario Deliotti Racing, finishing seventh in the standings with 62 points. He contested the 1979 Race of Champions at Brands Hatch, a non-championship Formula One event, finishing twelfth from nineteenth on the grid. During the 1979 season he also drove for Theodore Racing Hong Kong in a Wolf WR3 and WR4. He returned in 1980 with Colin Bennett Racing in a Fittipaldi F5A and F5B, finishing eighth in the standings with 11 points. In 1982 he again raced for Colin Bennett Racing in a March 811, finishing seventh with 10 points.
Musetti made a single appearance in the 1985 International Formula 3000 season with Lola Motorsport, driving a Lola T950 at Donington Park and finishing fifteenth.
In the late 1980s Musetti moved into sportscar competition in the FIA World Sportscar Championship. In 1986 he raced for Roy Baker Racing in a Tiga GC285 in the C2 class, contesting rounds including the 24 Hours of Le Mans, where the car retired after 95 laps. His co-drivers at Le Mans were Tom Frank and Mike Allison. He returned to the World Sportscar Championship in 1987 with entries in machines including a Bardon DB1 for John Bartlett Racing, the Roy Baker Racing Tiga GC286, and a Team Tiga Ford Denmark Tiga GC287. In 1988 he raced the Roy Baker Racing Tiga GC286 again. In 1990 he drove a Porsche 962C for Team Davey, including a seventeenth-place finish at Donington Park. In 1991 he raced a Porsche 962C for Team Salamin Primagaz, entering the 24 Hours of Le Mans but failing to qualify.
In 1991 Musetti entered one round of the British Touring Car Championship at Donington Park, driving a BMW M3 for BRR Motorsport and finishing thirteenth. In 2000 he competed in the British GT Championship with AC Automotive in a Chevrolet Camaro in the GT class.
Alongside his racing, Musetti maintained a career as a film and television stuntman. His television credits include The Avengers, Callan, Doctor Who (the serial The Crusade), Space: 1999, The Professionals, Minder, and Dempsey and Makepeace. His film credits include The Italian Job, The New Avengers, Superman II, An American Werewolf in London, Robin Hood: Prince of Thieves, Alien 3, and Midsomer Murders. He appeared on screen as Napier Hood Number 4 in the 1989 Batman film.