Soon afterward, at age 19, he became a finalist in the 1980 Lyric Opera of Chicago auditions. There, he was mentored by Walter Baracchi, the noted pianist-conductor who had been with Lyric Opera of Chicago for a decade, and previously with Milan's La Scala since the late 1950s. This launched a professional singing career for Negrini. In Chicago, he would go on to share the stage, and learn from Luciano Pavarotti, Mirella Freni, Alfredo Kraus, Jon Vickers, and scores of other notables. Among his most successful performances were his portrayal of the "rock star" Nanki-Poo in Peter Sellars's updated production of The Mikado, and his rendition of Don Ramiro in the Gian-Carlo Menotti production of La Cenerentola at the Kennedy Center in Washington, D.C. – a role he would eventually perform over 100 times with many different opera companies. During this period he also performed the role of David in Die Meistersinger with the Chicago Symphony Orchestra under Erich Leinsdorf.