Some of the greatest pieces of music are not just beautiful to hear, but beautiful to see as well. I'm not talking about operas or ballets, in which the music is combined with stage business, scenery, costumes, and the human form. I mean pieces of pure music that conjure images in the mind's eye.
Another piece featuring a bird is Ralph Vaughan Williams' The Lark Ascending. Another one-movement piece for solo instrument and orchestra, this one spotlights the violin. But before the violinist comes in soaring and singing, the orchestra lays down a soft, gently dissonant chord that just stays put for a long time in the background. It doesn't do anything. It doesn't go anywhere. It just establishes a sense of space, as when an artist begins a landscape picture by sketching in a horizon line. That chord, while it lasts, is the sky in which the lark does its skylarking.
This picture brings my mind back to Sibelius, and his final tone-poem Tapiola. Evoking the forest spirits of Finnish mythology, the piece features darting, flashing phrases of melody set against a backdrop of massive, static harmonies. I'll have to be spellbound if I ever hear this piece without thinking of gigantic, timeless trees holding up a canopy of branches and leaves, in whose shadow move strange, capricious things.
The art form known as the Tone Poem, or sometimes as a Symphonic Poem, is the thing to look into if you are interested in the possibilities of music you can see. I recommend searching for pieces by Franz Liszt, Antonín Dvořák, Peter Tchaikovsky, Richard Strauss, and Claude Debussy, some of whose tone poems were really inspired by paintings. Mathis der Maler by Paul Hindemith is practically a symphony based on this principle. Other composers you may or may not have heard of, who likewise excelled at such music, are discussed in the Wiki on this type of music, which I choose not to plagiarize here.