Sometimes you want to say that there has never been a clearer case of OCD in music. There are certainly obsessive qualities in the music: the compulsive hammering on a single rhythm, the seeming inability to stop the music from constantly hastening to the next climax. The sudden quiet, followed by more compulsive ranting. At times one feels that one is experiencing a mental disorder.
The piece that I feel might be the real historical precedent for Pettersson's way of composing is Schoenberg's equally troubling Erwartung, composed in 1909:
A symphony by Pettersson is akin to a stream-of-consciousness novel by James Joyce or Virginia Woolf. There are few traditional structural elements, which, paradoxically, makes the music perhaps more modernist than the music of some of the more well-known figures in modernism. I had always thought that Erwartung was an experiment in athematic stream-of-consciousness that had no heirs, not even in the music of Schoenberg himself. But I think that Pettersson, perhaps without realizing it, was proceeding on a similar path.
The phrases "stormy weather" and "lyrical islands" are used quite a number of times by the writer of the liner notes to the complete recordings, Andreas K. W. Meyer, and they seem appropriate. Pettersson, while exploring a wealth of atmospheric effects, often seems to create a dichotomy between a stormy mood and a lyrical one.
With one exception, I found all the symphonies both listenable and fascinating. The exception being the Symphony No. 12, "The Death of the Square", a choral symphony based on texts by Pablo Neruda. This is a frankly political work inspired by the events in Chile around the time of its composition. I don't believe Pettersson, on the evidence of this piece, to be a good composer for choir and I think it was a mistake to venture into the political field when all the rest of his work repudiates the whole notion of politics in music.
But the rest of the symphonies, while demanding and often grueling to listen to, do fascinate and have an uncompromising approach to music that is to be admired. The central group of works, nos. 5 through 9, written in the decade of the sixties, are probably the most accessible. The Symphony No. 9 will likely strain your powers of concentration with its single movement, seventy minute span. But in many ways it is the best of his symphonies with both powerful expression and the sense that it has a real coherence to it. The ending has a long, powerful unison passage for the strings ending with what I swear sounds like a plagal cadence!
Unfortunately, there does not seem to be a clip of it on YouTube. But there is still a box of the symphonies available from Amazon:
We can find the Symphony No. 8, atypically in two movements, in one of the few commercial recordings of Pettersson's work, with Sergiu Comissiona conducting the Baltimore Symphony. Here is the first movement: