Visit your smartphone's application downloader. Some devices, such as the iPhone, require users to create a financed account with the device manufacturer to access the application database and purchase software.
Download a music-identifying application, such as Shazam or SoundHound. Some applications offer a free trial of the software with a limited number of identifications. Purchase the application if you plan to tag more songs than the free trial permits.
Open the identifying application and press the "listen" or "tag" button while the commercial's music is playing. Most applications need about ten seconds of a song to identify the track and its artist. Although such applications are designed to identify music in noisy situations, try to eliminate unnecessary background sound for optimal tagging.
Wait for the application to finish listening to view the result screen. If the application is unable to find any results, consider holding the device closer to your television or computer speakers and try again.
Visit a television soundtrack database, such as Adtunes, which offers lists of the music used in movies, television programming and video games.
Click the "Television" link located on the navigation bar at the top of the website's home page and select "TV Commercial Music" from the drop-down menu.
Scroll through the list of posted commercials. Limit your results by post time or by using the search bar at the top of the page.