Export iTunes music library information (album, artist, track names) to CSV or spreadsheet format?

Make sure all the columns you want metadata for are visible in the playlist or library you're looking at. Then, select the tunes you want with shift-click or ⌘-click or whatever:

Then, hit ⌘+C to copy. This will allow you to paste what's visible in the iTunes playlist into any sort of spreadsheet you like:

It won't label the columns for you, but it'll do the trick quickly.

You can do File -> Library -> Export Library and get an XML file of your library metadata. From there it would be a relatively straightforward matter for a programmer to convert the XML data into a CSV, spreadsheet, or database.

For example, I made this quick Ruby script in about 10 minutes to get the artist, album, and track names from the XML and output a CSV. Note that it will only match tracks that have all 3 pieces of info provided, and that it requires the library file to be called "Library.xml" in the current directory:

require 'csv'

track = /<key>Name<\/key><string>(.*)<\/string>[.\s]*<key>Artist<\/key><string>(.*)<\/string>[.\s]*<key>Album<\/key><string>(.*)<\/string>/

file = File.open("Library.xml", "r")
contents = file.read

out = CSV.open("Library.csv", "w")

contents.scan(track) do |match|
  out << match
end

For enhancements/tools to work with ITunes probably the first place to go is Doug's Applescripts for iTunes. There are many useful scripts here.

On the page for Exporting Info there is this script that exports track information as a text file.

This script will write a discrete alphabetical list of your choice of the Albums, Artists, Album Artists, Composers, Genres, Shows, or Track Names in iTunes to a text file.

One more option: exiftool will also extract ID3 tags from music files. One of its many options is to put them in a CSV file, one line per input file. You can also limit which tags it will pull.