I'm not sure. If an artist uses colored pencil, has he/she created a drawing or a painting?
One thing I get sick of as a music scholar is the way people use the word "song". If you like the intense part of the Inception soundtrack, then no, you don't like that song. It's not a ****ing song.
Songs are sung. If this were a century ago, it would refer to the chanson tradition in France shortly after the fall of the Roman Empire, in which a solo singer would sing a poem according to form fixes, or a certain combination of verse/refrain with repeating melodic stanzas. Accompaniment was optional. That's a tradition that was followed up all the way through the 19th century in everything- even common folk songs.
The definition changed and evolved throughout the 20th century to embody all types of sung musical works. But that's the qualifier: singing.
If you want to talk about the Hans Zimmer soundtrack, it's an awesome PIECE you're listening to. It's not a ****ing song.