Yep, as Jimmy T said, rubbish in, rubbish out.
128 kbit MP3's are a very poor recording, and is usually what people record their music as its the Microsoft Windows default setting on the computers, unless you record from the CD or high definition source at suitable rates. CD's are 384 and Apple iTunes downloads are 256kbits.
Other recordings can vary below any of these levels due to the quality of the source.
Obviously, the bigger the file, the less music in the storage device.
Its a trade off.
I'd go for quality recordings in a bigger memory stick. They are cheap now days.
Ken