The main action, however, was over at the Waverley Stage. So while The 1975 served up a set of coffee table atmospherics and well-mannered pop hooks in the Gardens, Chvrches and Django Django all-but stole the show down the road with matching displays of electro-pop which one suspects would have Messrs Tennant and Lowe tapping a discreet toe to.
Both bands are much louder live than on record, with Chvrches' marriage of epic four to the floor techno and indie-pop sensibilities making for a euphoric experience. Django Django, meanwhile, are art school conceptualists to a man. Led on by two bag-pipers, the quartet sport matching panda-patterned white hoodies and play a percussive overture before launching into a blistering set of twenty-first century electro Merseybeat.
If this made for quite a spectacle, it was nothing compared with Pet Shop Boys, who opened a greatest hits set clad in spiky rubber jackets with It's A Sin, before a quartet of be-suited dancers wearing multi-coloured boxes on their heads joined them for Rent. With Minotaur heads a-go-go for Suburbia, projected backdrops gave nods to Gilbert and George and Kenneth Anger, transforming the arch English classicism of Tennant's lyrics and vocals into the wittiest of spectacles. While Tennant's umpteen costume changes saw him move from regal robes to scarlet fez and sparkly silver jacket, Lowe of course remained motionless behind his bank of keyboards.
First song after the bells was Go West, which transformed Princes Street into the biggest gay disco on the planet. If this opening musical sally is anything to go by, Edinburgh - and indeed Scotland - in 2014 is already a state of art.