Hi Linux lovers (just like me

)
I have a trouble with my MP3 player. I have a Philips mp3 player that can connect to PC USB to transfer music. For Windows, when i plug it in, M$ OS treats it as a removable disk. Transfer can be made by copying file as usual.
However, i cannot do the same to linux.
I tried mounting it using this command :
%mount /dev/sda1 mp3player/
mount: /dev/sda1 is not a valid block device
but it was not successful.
I also had a USB thumb drive and I can mount the USB thumb drive with the above command.
In short words, the mount command treats my USB thumb drive and the MP3 player as two different devices while M$
Windows treats them as the same kind of device (removable disk).
Do you know how to make the mp3 player work with Linux ?