When we first started producing 2-Minute Explainer videos for companies in 2004, we resisted the idea of putting music in technology marketing videos under the narration. It seemed sufficient to “bookend” the video with music in the opening (usually a “logo spin”) and closing. It seemed to us that if you’re trying to explain a serious concept like Business Intelligence or Service Oriented Architecture, the background music makes the video less serious and more commercial or “sales-y.” And background music can become tiresome after a couple of minutes.
Sales pitch or explanation?
On the other hand, if you’re making a straightforward product pitch, particularly one that runs only a minute or so, well-chosen music can significantly enhance the viewing experience. For example, here’s a sales pitch where the overall tone of the narration and visuals is casual and whimsical. It seems to need music.
Here’s an example of a fairly serious and technical video we created for Cisco which did not use music. The version on the left is straight narration. The narration in the version on the right is backed by some fairly serious music (Prelude in F-Major from Bach’s Well-Tempered Clavier).

Narration + Music. (music is a sample of royalty-free music from AudioJungle)