I shoot fashion, dance, drama and fitness and write and record music to go with the images in the video. The video edit comes first and I then write, record and re-arrange the music to work with the edit, rather like scoring a movie.
Here's why I do it:
Visual art is a record of beauty and I take images that, I hope, show beauty in an interesting way. I take my cue from Hegel who said "Beauty is born of the spirit and born again", that is, it comes from and is recreated by the human spirit. He wrote in the early 19th century that beauty can only be manifested in the human form, because it alone can show freedom and spirit.
Essays on this are on site.