Question: What is the profession shared by Philip Glass and Antonio Salieri 
Context: La passione di Gesù Cristo is an oratorio by composer Antonio Salieri that uses a libretto by Metastasio.  While many composer's set music to this libretto, Metastasio is recorded to have said before Joseph II, Holy Roman Emperor that Salieri's setting "was the most expressive of any written on this poem."  The work premiered in Vienna, Austria during the advent season of 1776. The Philip Glass Ensemble is a musical group founded by composer Philip Glass in 1968 to serve as a performance outlet for his experimental minimalist music.  The Ensemble's instrumentation became a hallmark of Glass's early minimalist style.  After Glass wrote his first opera, "Einstein on the Beach", for the Ensemble in 1976, he began to compose for other instrumentation more frequently, but he still retains the core ensemble instrumentation. Amadeus is a play by Peter Shaffer, which gives a highly fictionalized account of the lives of the composers Wolfgang Amadeus Mozart and Antonio Salieri.  First performed in 1979, "Amadeus" was inspired by a short 1830 play by Alexander Pushkin called "Mozart and Salieri" (which was also used as the libretto for an opera of the same name by Nikolai Rimsky-Korsakov in 1897). Tarare is an opéra (tragédie lyrique) composed by Antonio Salieri to a French libretto by Pierre Beaumarchais.  It was first performed by the Paris Opera at the Théâtre de la Porte Saint-Martin on 8 June 1787.  Salieri also reworked the material into an Italian version retitled "Axur, re d'Ormus" with libretto by Lorenzo da Ponte, which opened in Vienna in January 1788. Glassworks is a chamber music work of six movements by Philip Glass.  It is regarded as a characteristically Glass-like work.  Following his larger-scale concert and stage works, "Glassworks" was Philip Glass's successful attempt to create a more pop-oriented "Walkman-suitable" work, with considerably shorter and more accessible pieces written for the recording studio.  The studio album was released in 1982. Per la ricuperata salute di Ofelia (For the recovered health of Ophelia), K.  477a, is a solo cantata for soprano and fortepiano composed in 1785 by Antonio Salieri and Wolfgang Amadeus Mozart, formerly thought to have been enemies, and a third, unknown composer, Cornetti, to a libretto written by the Vienna court poet Lorenzo Da Ponte.  It is speculated that "Cornetti" may refer to Alessandro Cornetti, a vocal teacher and composer active in Vienna at the time, or that it is a pseudonym of either Salieri or Stephen Storace, a composer who organized the collaborative work to honor his famous sister.  The music had been considered lost until November 2015, when German musicologist and composer Timo Jouko Herrmann identified the score while searching for music by one of Salieri's ostensible pupils, Antonio Casimir Cartellieri, in the archives of the Czech Museum of Music in Prague. Tara Hugo sings Philip Glass is a 2012 album by mezzo-soprano and actress Tara Hugo of songs of composer Philip Glass.  The recording project was initiated by Glass himself who asked collaborator and producer Kurt Munkacsi to present pieces that Glass had composed for larger music ensembles as a song recital for small ensemble.  The recital album includes songs Glass had composed with or for singers Leonard Cohen (Book of Longing), Natalie Merchant, Mick Jagger and poet Allen Ginsberg.  The album also includes new arrangements by Trevor Gureckis of Glass instrumental music set to new lyrics written by Tara Hugo. A Toltec Symphony (also known as Symphony No. 7 "A Toltec Symphony") is a 2005 symphony by Philip Glass.  The National Symphony Orchestra commissioned Glass to write it to commemorate the 60th birthday of conductor Leonard Slatkin.  Slatkin conducted the debut concert on January 20, 2005 at the Kennedy Center, which Philip Glass attended. Philip Morris Glass (born January 31, 1937) is an American composer.  He is widely regarded as one of the most influential musicians of the late 20th century. Antonio Salieri (] ; 18 August 17507 May 1825) was an Italian classical composer, conductor, and teacher.  He was born in Legnago, south of Verona, in the Republic of Venice, and spent his adult life and career as a subject of the Habsburg Monarchy.
Answer: composer, conductor