BEFORE YOU CLICK THIS QUESTION! Think. How long do you think the longest concert in history is (or will be)?

I must agree with Alberich to some degree that this performance of John Cage's "ASLAP (as Slowly as Possible) doesn't really constitute a concert. Though I arrive at that conclusion for reasons entirely lexicographic.

When you consider that the keys of the organ are being played by lead weights, and that it is in a church, and the that the vast majority of the time that there is no audience this piece simply doesn't meet the definition of concert in either the Harvard Music Dictionary or the Grove Music Dictionary.

I've heard versions of this ASLAP on the short side of 20 minutes and on the long side of around 2 hours, both of which I enjoyed. Those were concerts because its possible for a an audience to attend and comprehend the music. When ASLAP is stretched out to such preposterously long stretches it has more in common with Rothko painting than it does with music.

Furthermore I have a problem with the way the piece is being performed. The instructions apply to the people performing as well as the tempo of the piece, which is not being done in Halberstadt.

I think the merit of this "concert" is simply as an entry point for people into avant-garde music.

There several other pieces that I think would constitute longest concert.

Vexations by Erik Satie runs about 18 hours.

As Alberich already mentioned Mysterium, had it been completed, was planned to take a week.

Stockhausen's aus den tagen lieben does not specify an exact duration, though if you actually follow the instructions literally (most performers don't for good reasons) the performance would take about 10 days.

I'd heard of that before, so I guessed that that's what the question would be about. I find it interesting to think about how a "performance" that starts now will still be going on for long after I'm dead, and theoretically my very distant descendants will be able to attend the same performance as me. There's something kind of poetic about that. But I doubt it will actually last for 639 years; any manner of things could happen within the next few years to end it, not to mind the next 600 years. I wonder how long it will really go on for.

Sorry, but I have to disagree with you; because I don't consider the-----------------what should it be referred to, instead of as a real music of piece, a composition, a concert?

Because it isn't any of the above: simply an attention seeking gimmick - "pure", nothing: a bit of nonsensical "rubbish".

What would be, have been the longest concert ever, were it to have been completed by the composer, was the "Mysterium" of Alexander Scriabin. It was conceived of when performed high in the Himalaya mountains, as bringing about the end of the world: http://en.wikipedia.org/wiki/Mysterium_(Scriabin)

A video performance of the first segment; realization of, by another: not the composer, if I understand its history correctly: http://www.youtube.com/watch?v=mSWuUuySFyU

Alberich