The AIYF has evolved to embrace a wide range of the arts since it started in 1972. "It began as a music festival - a classical festival - and from that it grew into classical dance and a bit of theatre," says artistic director Stewart Aitken.
He came to this role nearly three years ago from Wigan Pier Theatre Company. "We now have a bigger jazz programme, traditional music and different types of dance, so it's very much a multi-arts festival, as opposed to a music festival now."
Stewart is keen to increase box-office income and is promoting the festival as a summer attraction for families, with daytime events and keenly-priced family tickets.
There are 10 city-centre stages with free performances on the opening Sunday and daily free shows for shoppers in Aberdeen's new shopping centre, Union Square.
New educational ventures this year include the AIYF chamber music project, which offers 20 experienced young musicians the chance to join a week of intense tuition and performance, led by members of the Hebrides Ensemble and their director Will Conway.
Other free events during the 10-day festival include an opera masterclass with international soprano Lisa Milne, and an extended festival takes performers to village halls throughout the region and bigger towns such as Arbroath, Montrose and Inverness.
Among international performers are the Norwegian Girls Choir, the Icelandic Youth Symphony Orchestra, a Russian string ensemble VIVAlini and the Hungarian Dance Academy.
This year's festival closes with an International Variety Gala at His Majesty's Theatre on August 7.