"My music has no significant rhythmic construction, but when I write music, I am always very concerned about the concept of time."

Takemitsu had little interest in classical forms. He did not write symphonies, use the principles of sonata form, compose scherzos or construct music which had an inevitable progression towards a climax or goal.

Instead his music could be described as sectional, gradually changing and unfolding in a free, spontaneous way that transports the listener into different regions or landscapes.

Rather than telling any kind of story or portraying a particular sequence of events Takemitsu's music 'suggests' atmospheres. Images of mountains, water and trees are typical, things that he described as helped rather than governed by man.

For him sound is nature and sense is colour. One scene or image can provide the foundation for a whole piece - one chord or wisp of melody can be seen from many alternative view points. This approach meant that each new piece eventually discovered its own unique form where small sections of music are combined, added-on or juxtaposed, with a subtle variety of transformations.

Tree Line can be seen as such a construction with fifteen independent miniatures arranged in an intuitive order each marked by a rehearsal letters (A - N ) in the printed score.