He was invited to the
Glyndebourne Festival in 1962, to sing Count Almaviva in Mozart's
Le nozze di Figaro. Bacquier made his American debut at a Carnegie Hall concert, including the premiere of a new production of
Tosca with
Birgit Nilsson and
Franco Corelli. He also sang frequently at the
Philadelphia Lyric Opera Company between 1963 and 1968, making his debut on 22 February 1963 as Zurga in Bizet's
Les pêcheurs de perles with
Ferruccio Tagliavini as Nadir and
Adriana Maliponte as Leïla. His other roles in Philadelphia included Nilakantha in
Lakmé opposite
Joan Sutherland in the title role, Germont with Sutherland as Violetta and
John Alexander as Alfredo, Iago in Verdi's
Otello, Scarpia, and Escamillo in Bizet's
Carmen. He made his debut at the
San Francisco Opera in 1971 as Michele in Puccini's
Il tabarro. In 1978, he appeared at the Metropolitan Opera as Golaud alongside
Teresa Stratas as Mélisande. A reviewer of
The New York Times noted "the precise, fluent inflection of his singing, which has to be delicate and yet weighted with feeling".
Thomas Allen classified Bacquier as a 'singer-actor': "...a voice and a knowledge of his body language such that one can be forgiven for asking the question 'Is this an actor singing or a singer acting?'". Though closely associated with the French repertory, especially Golaud, Bacquier resisted being typecast as a 'French baritone' and added many Italian roles to his repertory, in addition to those already mentioned, such as the Verdi roles Renato in
Un ballo in maschera, Melitone in
La forza del destino, Posa in
Don Carlos and
Falstaff, as well as comic roles such as Mozart's Leporello in
Don Giovanni and Alfonso in
Cosi fan tutte, among others. In 1975 a critic reviewing Donizettis's ''
L'elisir d'amore'' commented that "broad humour is quite foreign to Bacquier's nature ... his doctor [Dulcamara] is a serious
Archie Rice type, no caricature but a real man weighed down by his own charlatanism and basically sad that mankind is so gullible". Rare tentatives in non-French and Italian repertoire came with Wolfram in
Tannhäuser by Wagner, praised by
André Pernet, and the title role in
Boris Godunov by Mussorgsky in 1971 (both sung in French translation). By the 1980s, Bacquier had arranged his repertory to suit the evolution of his voice, from a high tessitura to low, and concentrated on roles he felt were more substantial. Many of his portrayals are preserved in an extensive discography. For
The Record of Singing, Volume 5 : 1953–2007 (from the LP to the digital era), his recording of "Une puce gentille" from Berlioz's
La damnation de Faust was included on disc 7. ==Premieres and song==