The atmosphere sharpens, the chattering stops, everyone's eyes are fixed to the stage, writes BBC News Online's Deirdre Kelly.

The atmosphere sharpens, the chattering stops, everyone's eyes are fixed to the stage the stamp stamp of people's feet gets louder and arms are thrust aloft. At last, U2 are back in Scotland for an unexpected, but most welcome two-date gig in Glasgow.

On Monday, concert-goers at the city's SECC could hardly believe they were watching one of the world's biggest live bands. A week ago none had been expecting to see Bono and the boys performing their Elevation tour.

The lead singer thanked the dedicated followers for queuing up to snap up the gold-dust tickets and he gave a tongue-in-cheek apology to those who had planned to watch telly that evening.

Bono was the showman - clad in cool black leather and donning those dark shades we expect a popstar of his standing to wear. (But, may I add, sporting noticeably comfy black trainers.) His voice is what helps to make U2 one of the best. He is also a performer who teases and controls his audience.

To applause from fans he peeled off his shades during Staring at the Sun and rubbed his eyes under the glare of the venue lights. He took a T-shirt from the crowd to wipe his sweaty face, he sipped water from the bottle of a can't-quite-believe-it fan, he told his followers "if we bomb in Glasgow then that's the end of U2". Bono knows what buttons to push, and push he does.

Indeed his god-like status allows him to get away with political statements on the G8, the UN Council, Jubilee 2000 and Northern Ireland - his fans appear to love him all the more for it. Guitarist the Edge really knows how to make his talent sing

For many a U2 concert-goer the live performance is a spiritual experience. When Bono dedicated a song to his father, it wasn't just a case of "and this one's for me dead dad".

Bono tells us it's to celebrate the new body of his pa, whose old cancer-ravaged one is now gone forever.

During the latter stages of the Elevation tour, the lead singer's dying father was mentioned nightly - such a dedication helped to make that all-important connection with the audience.

U2 is a band of simplicity, a lead singer, lead guitarist, bass player and drummer. But they do have harmony, they do have percussion and they do have a chorus line - thanks to the fans. They make the concerts - they know the words, they know the tunes, they know to breath at the right moment and they know when to keep silent. The U2 fan is well practised, he rehearses in the bath, rehearses in bed and rehearses in the car.

On Monday we all got the chance to be the chorus line, to be part of the beat that resonated throughout.