Verify that your Samsung T-Mobile phone is set up to play music. Select "Menu" on the phone. Then select "Settings," "Phone Settings," "USB mode" and "Media Player." This will set the phone up as a media player.
Plug in the USB cable that came with your phone into the phone. Plug the other end into the USB port of the computer.
Open Windows Media Player on your computer. This can be found by clicking on the "Start" menu on the bottom left of the computer screen. Move the cursor to "Programs." A new window will open which will have the Windows Media Player icon in it. Click on the icon.
Locate the folder in which you have saved the music that will be transferred to the phone. Drag the files of the songs you want to transfer to your Samsung phone into the "Sync list" that is found on the right side of the screen of the Windows Media Player.
Locate the "Start Sync" button in Windows Media Player, in the lower-right corner of the Windows Media Player screen. Click on it.
Wait for the transfer process to end and remove the cord. You have now uploaded music onto the Samsung T-Mobile Phone.