Firstly, apologies if this is better suited to MusicFans. I'll be happy to post there if necessary.
I'm really confused about 'Serial composers'. While studying Igor Stravinsky, in his later life, he was regarded as a 'Serial composer'. I would love to know if composers despised this categorisation but we are digressing.
From his Wiki page, from 1945-1968.
This began Stravinsky's third and final distinct musical period, the serial (or twelve-tone) period, which lasted until his death.
Not just Igor, there are lots of them.
Source: Google search
When we say 'twelve-tone' we mean the Chromatic scale don't we?
The twelve Major and Minor's aside - this is a new scale, a scale which uses all the notes.
However, when Stravinsky was setting about his work or any composer of that matter it's up to you what notes you use, you could use all twelve notes in any scale but this doesn't class you as a Serial Composer does it? I could have a piece in G Major and still use whatever I wanted to with the use of accidentals and naturals?
In a way, we are always writing music using Serialism then? I must admit I'm not very good with scales yet, I don't know them off the top of my head :(
All 12 notes are thus given more or less equal importance, and the music avoids being in a key.
What is it about this movement, of which people believe Schoenberg's use was of it was most important, made it such a worthwhile landmark in the evolution of classical music?