Tina Byrom, who resigned from Bilborough sixth-form college, Nottingham in May 2002, is accused of giving pupils the answer to a pre-released question on Bach's chorals, the General Teaching Council for England heard.
Robert Bourns, presenting officer, said the May 2001 exam papers were returned to the college by the exam board Edexcel after similarities were spotted on a number of papers.
Students interviewed by Jo Joynes, an independent consultant, complained of having had only one lesson on the chorals, in which they were told to copy an answer down from the board.
David Sibley, also a music teacher at the college, told the GTCE that Mrs Byrom had asked him for a rough working of an answer to the exam question, which he then recognised on some of the students' exam papers.
"Many of the returned 2001 papers displayed a number of complex and unusual elements in their answers and a knowledge of harmonic practice that would be unlikely among a group of 16 to 18-year-old music students," he said.
Mr Sibley later set a mock exam question to the same group of students, using the same question as the 2001 paper but in a different musical key.
"Mock exam papers taken after the 2001 paper showed a distinct lack of the sophistication demonstrated in the 2001 exam despite the fact that it was exactly the same question but in a different key," he said. Mrs Byrom, accused of unacceptable professional conduct, has yet to give evidence. The case was this week adjourned until a later date.