Watch FMovies. In 1990, guitarist and vocalist John Martyn embarked on a series of concerts at London's Shaw Theatre, to promote his comeback album 'The Apprentice'. These concerts were filmed and then released on videocassette on the same album. Many years later, a DVD release is now available for the first time, much to the delight of fans of Martyn and his music; the performance is also notable for the presence, as a guest on guitar, of Dave Gilmour of Pink Floyd.