[2][3] In addition to choreographing Jailhouse Rock, Romero worked with performers and choreographers who included Gene Kelly, Hermes Pan, Stanley Donen, Fred Astaire, and Michael Kidd in films that included On the Town and An American in Paris, in which he also performed during ballet sequences.
He also staged dances as in the films Easter Parade, Seven Brides for Seven Brothers and Kiss Me Kate and television shows.
[4] The family moved in 1921 to Los Angeles, where his older brother Carlos was working as a dancer in silent films.
[6] In 1941, after working in a print shop, Romero registered with Central Casting and was hired as a dancer by Warner Brothers' dance director LeRoy Prinz.
He and the studio dance troupe performed in a number of Columbia films, including Eadie Was a Lady and The Thrill of Brazil, both with Ann Miller.
[8] Romero left Cole's troupe in 1947 and shortly afterwards was hired by Metro-Goldwyn-Mayer dance director Robert Alton as an assistant choreographer.
Romero also choreographed the "Thou Swell" dance performed by June Allyson and the Blackburn Twins in that film.
[9] Romero also worked as assistant choreographer in Easter Parade and in On the Town, in which he appeared as one of the two sailors dancing with Kelly in the Day in New York ballet.
He then was an assistant to Alton in Annie Get Your Gun, and worked with Judy Garland on the "I'm An Indian Too" number, performing as well as choreographing.
Daniels performed with Astaire in the "Shine on Your Shoes" number, set in a penny arcade, and subsequently went into show business full-time.
[17] In 1976 he returned to MGM to stage a dance number with Gene Kelly and Fred Astaire in That's Entertainment Part II.