Music stops in a card that is set to “Continue Previous Piece”

Question:

I have downloaded a piece of free mp3 music from the Internet to use as BGM. The music stops playing despite the fact that it is set to "Continue Previous Piece." When I select music separately for every single Card, the music starts over again with every Card. It is impossible to play one piece of music continuously. It only happens when I use music downloaded from the Internet.

Answer:

Depending on the source of the music, it may not be possible to seek (move to the middle of a piece of music).
Converting the music to AAC by selecting "Create AAC version" on iTunes will solve this problem.