The LA Philharmonic will take centre stage at Tynecastle stadium later for the official start of the Edinburgh International Festival.
About 15,000 free tickets were snapped up in 90 minutes for the free open air concert which will feature music from Hollywood films.
Friday also marks the start of the Edinburgh Fringe, which features 3,841 shows in 323 venues.
Performers from 63 countries include Craig Ferguson and Basil Brush.
There will be Fringe debuts by performers including stunt cyclist Danny MacAskill and Parks and Recreation star Nick Offerman.
Some big-name comedians, such as Eddie Izzard, Omid Djalili, Russell Howard, Nina Conti and Stephen K Amos, are going to try out work-in-progress shows,
Audiences have also been urged to take a chance on new Fringe shows, and look beyond the usual big names and venues.
An arcade-style Inspiration Machine has been set up on the Mound which randomly displays videos from Fringe artists at the push of a button in a bid to persuade audiences to seek out something different.
The opening event at the Edinburgh International festival has become as much of a tradition as the closing fireworks concert.
It is, though, the first year it has been a concert and outside the city centre – at Tynecastle Stadium.
A capacity crowd of 15,000 is expected for the concert performed by the LA Philharmonic under Gustavo Dudamel.
The stadium is also one of more than 300 which will be used by the Edinburgh Fringe.
An expanded number of roads in the city centre will be closed or restricted during festival time following complaints from locals.
The Fringe and the International Festival both run until 26 August.