: Play the video on one device and use an app like Shazam or SoundHound on another to listen and identify it.
: If the video contains singing, type a unique phrase from the lyrics into a search engine.
If you have the video file, you can identify the music using these common methods:
Determining the exact music or "piece" for a file named based solely on its filename is not possible because "IMG_XXXX" is the generic naming convention used by Apple devices (iPhone, iPad) and many digital cameras for photos and videos.
: You can use the "Search a song" feature in the Google app by humming or singing the melody.