Up on the cloud line.

Tunes in my head: The Night Watch by King Crimson
Books of a page: Why You Should Read Kafka Before You Waste Your Life by James Hawes
Atmosphere: Alert

There's a certain bravado that accompanies going up on stage in front of five hundred, two thousand, seventy thousand people, and just playing whatever comes through the conduits of your soul, in going up and improvising in front of them.

It takes skill, too, of course. But mainly absolute guts. Who says the audience will be there with you, neccesarily? It's by no means definite. Sometimes they can listen to the uplifting, "type II" jamming and be completely turned off. Sometimes they can hear total improv and just be entranced by it.

Take for example, King Crimson's Trio. During a late night gig, at three in the morning, the band had just ripped through particularly energetic and heavy versions of their Starless and Bible Black material, concluding that section with a dissonant, atonal improv. From the chaos and carnage of this assault came a sole flute line, and from there the composers took up interweaving melodic lines. Soon there was a three pronged melodic piece, the bass guitar, flute and violin interlocking and playing around each other's gaps. It was so profound that the band's drummer, Bill Bruford, did not play a single note, realising that adding percussion to this gorgeous improv would merely destroy its integrity.

The audience had to be completely in on it, as well. If someone had yelled in the middle of the piece, the integrity would be ruined, the beauty of this completely improvised moment would be destroyed totally. Instead, the audience sat in silence, perhaps not realising that this was a moment of invention.

And the result is heard on Starless and Bible Black. Pieces of absolute beauty, something sublime, gorgeous.

On the other end of the scale comes what is affectionately titled "The Went Gin". At The Great Went in 1997, Phish launched into a version of the song Bathtub Gin that seemed at first ordinary.

Within ten minutes they had launched from a mid tempo vamp to a high paced improvisational flurry that transcended composed music. They had never done anything this potent, this uplifting before - and never would again. The final six minutes were quite possibly the six best minutes of music ever, period. A double time melodic vamp which repeated in absolute nirvana.

Sure, improv is at best risky, but when it goes off, it's heavenly. It just defies all definition, all words.