Motorola

Ok, so I recently got a 2g memory chip thing for my phone. The wonderful thing about it is that I can put every single one of my favorite songs on it. The horrible thing about it is, when I have all that music on there, the music player won't load...does anyone know of a better music player out there that my phone could handle and how exactly to get it to my phone in working condition? My fiance swears there must be...I sort of doubt that he's right though...