It is late afternoon and in a room darkening by the minute because of an all-too-familiar power cut, Shaden Shabwan, just 10 and a study in concentration, plays a Czech folk tune on an upright Yamaha piano as her teacher wills her to avoid mistakes. It is test day for piano students at the Gaza Music School, where Shaden is in her second year. Across the corridor, her classmate Abdel Aziz Sharek, also 10, is just as focused. Accompanied on ouds and tabla, he dexterously picks out a mesmerising classical longa on the qanun, the zither-like instrument that has been central to Arab music for a millennium or more. Abdel Aziz takes his regular studies as seriously as he evidently does the music. "I want to be a doctor," he explains. "But I will keep playing. I will be in a band at the same time."