Giacomo Antonio Perti
Giacomo Antonio Perti( 6 June 1661 – 10 April 1756) was an Italian composer of the Baroque era.
He was mainly active at Bologna, where he was" Maestro di Cappella" for sixty years.
He was the teacher of Giuseppe Torelli and Giovanni Battista Martini.
Apollonius Cronus
Apollonius Cronus( fl. 4th century BCE) from Cyrene was a philosopher of the Megarian school.
Very little is known about him.
He was the pupil of Eubulides, and was the teacher of Diodorus Cronus, as Strabo relates: Apollonius Cronus, was from Cyrene, ... being the teacher of Diodorus the Dialectician, who also was given the appellation" Cronus," certain persons having transferred the epithet of the teacher to the pupil.
The epithet" Cronus" roughly translates as" old fogey".
Rubellius Blandus
Rubellius Blandus was a Roman, native of Tibur( Tivoli, Italy).
He was the first Equestrian of Ancient Rome to teach rhetoric and thus made it more respectable( Sen., Controv. 2, 5).
He was the teacher of Papirius Fabianus, who was in turn the teacher of Seneca the Younger.
His grandson Gaius Rubellius Blandus was a suffect consul of 18.
Alonso Mudarra
Alonso Mudarra( c. 1510 – April 1, 1580) was a Spanish composer of the Renaissance, and also played the vihuela, a guitar- shaped string instrument.
He was an innovative composer of instrumental music as well as songs, and was the composer of the earliest surviving music for the guitar.
Periclytus
Periclytus, a sculptor, who belonged to the best period and to one of the best schools of Greek art, but of whom scarcely any thing is known.
He is only mentioned in a single passage of Pausanias( v. 17. § 4), from which we learn that he was the disciple of Polykleitos, and the teacher of Antiphanes of Argos, who was the teacher of Cleon of Sicyon.
Since Polycleitus flourished about b. c. 440, and Antiphanes about b. c. 400, the date of Periclytus may be fixed at about 420 BC.
Philip Cranmer
Philip Cranmer( 1918–2006) was an English teacher of and composer of classical music.
Der Doppelgänger
"Der Doppelgänger" is one of the six songs from Franz Schubert's "Schwanengesang" that sets words by Heinrich Heine for piano and tenor voice.
It was written in 1828, the year of Schubert's death.
Jean Mouton
Jean Mouton( c. 1459 – 30 October 1522) was a French composer of the Renaissance.
He was famous both for his motets, which are among the most refined of the time, and for being the teacher of Adrian Willaert, one of the founders of the Venetian School.
Barbara Goleman
Barbara Ann Goleman is an American secondary- school teacher of English literature and winner of the 1969 National Teacher of the Year award.
Franz Schubert
Franz Peter Schubert (31 January 179719 November 1828) was an Austrian composer of the late Classical and early Romantic eras.
Despite his short lifetime, Schubert left behind a vast oeuvre, including more than 600 secular vocal works (mainly lieder), seven complete symphonies, sacred music, operas, incidental music and a large body of piano and chamber music.
His major works include the Piano Quintet in A major, D. 667 ("Trout Quintet"), the Symphony No. 8 in B minor, D. 759 ("Unfinished Symphony"), the ”Great” Symphony No. 9 in C major, D. 944, the three last piano sonatas (D. 958–960), the opera "Fierrabras" (D. 796),
the incidental music to the play "Rosamunde" (D. 797), and the song cycles "Die schöne Müllerin" (D. 795) and "Winterreise" (D. 911).
Born in the Himmelpfortgrund suburb of Vienna, Schubert's uncommon gifts for music were evident from an early age.
His father gave him his first violin lessons and his older brother gave him piano lessons, but Schubert soon exceeded their abilities.
In 1808, at the age of eleven, he became a pupil at the Stadtkonvikt school, where he became acquainted with the orchestral music of Haydn, Mozart, and Beethoven.
He left the Stadtkonvikt at the end of 1813, and returned home to live with his father, where he began studying to become a schoolteacher; despite this, he continued his studies in composition with Antonio Salieri and still composed prolifically.
In 1821, Schubert was granted admission to the Gesellschaft der Musikfreunde as a performing member, which helped establish his name among the Viennese citizenry.
He gave a concert of his own works to critical acclaim in March 1828, the only time he did so in his career.
He died eight months later at the age of 31, the cause officially attributed to typhoid fever, but believed by some historians to be syphilis.
Appreciation of Schubert's music while he was alive was limited to a relatively small circle of admirers in Vienna, but interest in his work increased significantly in the decades following his death.
Felix Mendelssohn, Robert Schumann, Franz Liszt, Johannes Brahms and other 19th-century composers discovered and championed his works.
Today, Schubert is ranked among the greatest composers of Western classical music and his music continues to be popular.

Question: Who was the teacher of the composer of song Der Doppelgänger?
Answer: Antonio Salieri