Version 0.4b of LetterMeister has just been announced in FreeCode. As described in the LetterMeister project's FreeCode page, the update now includes music in the desktop version. Some improvements have also been made to the quality of scaled graphics as they appear in the game.
It is possible that the graphics improvements may have a small performance impact depending on your graphics card. If you do experience a problem, you are invited to report the problem either on the LetterMeister Facebook page or by e-mailing the author directly.
Download LetterMeister for free here: http://lettermeister.javamex.com/