trackFromSource.js

var singleString = 'Some Artist - Some Title';
var duration = 600; // length in seconds (required!)

// ideally, you have an object with the artist and title separate (and maybe credits!)
// you can use soundtrack.trackFromSource('object', ... , ...) for this
// see https://github.com/martindale/soundtrack.io/blob/soundtrack.io/lib/soundtrack.js#L326-L352
// however...
// if you only have a single string (like youtube), you can do this...
var parts = util.parseTitleString( singleString , function(parts) {
  
  // collect the artist BY ITS SLUG – this is normalization
  // it will find the first matching artist (i.e., first come first serve for names)
  Artist.findOne({ slug: slug( parts.artist ) }).exec(function(err, artist) {
    // doesn't exist?  create one.  you'll have to save it, though.
    if (!artist) artist = new Artist({ name: parts.artist });
    
    // similarly, find a track (normalized by slug(title), but only with the located artist
    // this will fail if it's a brand new artist, and will subsequently create one
    Track.findOne({
      _artist: artist._id,
      slug: slug( parts.title )
    }).exec(function(err, track) {
      // no track found, create one with the title
      if (!track) track = new Track({ title: parts.title });
      
      // set the track's artist to the one we found before
      track._artist = artist._id;
      // set its duration (this is MANDATORY or track advance events won't be broadcast!)
      track.duration = duration;
      
      // save artist first...
      artist.save(function(err) {
        // then save the track...
        track.save(function(err) {
          
          // all done!
          // do some callback here, for example with `async`:
          // done( null , track )
          
        });
      });
      
    });
    
  });
});

You'll find the current parseTitleString code insightful on how we extract "additional artists" from things like remixes. I keep a standalone version here so recommendations can be provided.

Also, direct audio streaming from soundtrack may interest you!