A piano teacher from Milton Keynes who groomed a young pupil by exchanging explicit phone photographs with her has been jailed for 22 months.
Philip Cunningham, 40, of Martinique Meadows, Bletchley, sent pictures of himself performing sexual acts and encouraged her to do the same.
Cunningham received 4,000 text messages from the 14-year-old girl, who is now 15, and he sent her 2,000.
Judge Rupert Mayo said: "It was a fundamental breach of trust."
Cunningham, a graduate of the London College of Music, was described as a peripatetic teacher at local schools in the Northampton area.
Prosecutor Michael Magee said: "He was in a position of trust and groomed the girl, inciting her to send him images.
"He specified what he wanted to see and sent images of himself to her."
He was caught when a friend of the girl confided in her mother about the teacher sending her pictures.
In a victim impact statement the girl's parents said she had been an A grade student until Cunningham groomed her.
Cunningham, a father of two, pleaded to possessing 14 indecent images of a child at Level 1, the least serious level of five levels, one of making an indecent image of a child at Level 2 and one of making an indecent image of a child at Level 1.
The offences happened between 1 October 2011 and 13 January last year.
Defence barrister Simon Hunka said Cunningham had a successful professional career that was now "completely ruined."
He said: "He does not seek to blame the girl. Every single thing that happened was a result of him. It is a grooming case."
Judge Mayo said: "A teacher is in position of sacred trust and if that is broken it is a very serious matter.
"What you did was to manipulate a child into a situation where she would do what you told her."