He played multiple instruments, including the guitar, mandolin, mandolincello, sitar, accordion and piano, composed more than 40 film scores and countless library music tracks, and was renowned for his whistling technique.

Alessandroni can be heard as the whistler on the soundtracks for Sergio Leone's films, including the Dollars Trilogy, Once Upon a Time in the West, and Pervirella.

[6] The group, which included his wife, Giulia De Mutiis [it], performed wordless vocals on several Italian movie soundtracks.

[7] Most notably, I Cantori Moderni are featured on the song "Mah Nà Mah Nà", written by Piero Umiliani for the 1968 Luigi Scattini mondo film Sweden: Heaven and Hell (Italian: Svezia, inferno e paradiso [it]) and popularized on The Muppet Show.

The Man's Mine (1969), Lady Frankenstein (1971), The Devil's Nightmare (1971), The Mad Butcher (1971), Seven Hours of Violence (1973), Sinbad and the Caliph of Baghdad (1973), Poker in Bed (1974), White Fang and the Hunter (1975), Blood and Bullets (1976), L'adolescente (1976), La professoressa di scienze naturali (1976), The Opening of Misty Beethoven (1976), Women's Camp 119 (1977), Killer Nun (1978), L'imbranato (1979), and Trinity Goes East (1998).