 Alkan became a favourite of his teacher at the Conservatoire , Joseph Zimmermann , who also taught Georges <unk> , César Franck , Charles Gounod , and Ambroise Thomas . At the age of seven , Alkan won a first prize for solfège and in later years prizes in piano ( 1824 ) , harmony ( 1827 ) , and organ ( 1834 ) . At the age of seven @-@ and @-@ a @-@ half he gave his first public performance , appearing as a violinist and playing an air and variations by Pierre <unk> . Alkan 's Opus 1 , a set of variations for piano based on a theme by Daniel <unk> , dates from 1828 , when he was 14 years old . At about this time he also undertook teaching duties at his father 's school . Antoine Marmontel , one of Charles @-@ Valentin 's pupils there , who was later to become his <unk> <unk> , wrote of the school : 
