The clarinet version of "Baby" is to be played in B-flat at a time signature of 4/4. The actual notes are:
Edcd ef a | edce ef f | edcd eddf | ff fagg g
eacd c | eac d | eacd c | ac d e | aac d e | aac d
eedc dcdc | dc d | ebc d c | ad d e a | d c eee | d e
dddc b c | eed e | e d d ddcd | c d eede | c d c d | cd a c
c d c d | cd g c | cd cd | cd a c | cd c cccd | de eedc
eea c d e | d d c b c b c e | d e ee | dcd c dd e | cd c eed
cd d eed | cd d eed | c c de | c c de | ccde ccde | d e ed
c e g | cc c c cc | c dd ee | eede c d | c d cd a | c c d | c d cd a
c c d | c d cd a | c cd c | cccd de | c d c d | cd a c | c d cd
There. Of course you'll want to find, or write, some sheet music for these notes so that you can add in rests and dots, and indicate how long the notes should be played in relation to the 4/4 time signature.
If these notes don't work out for you, then try running a Google search on your question. Chances are good that you'll find complete music sheets and performance videos somewhere online. A lot of people who share their music are also willing to share their music sheets, so a quick perusal of YouTube might also be of some help to you. As an added benefit to finding sheet music through YouTube, you'll have an idea of how the song will sound when you play it yourself.
Finally, you can always check your local book or music shop to see if they sell Justin Bieber sheet music books. These books contain multiple songs, so you'll be able to play more of his songs than just Baby.
Edcd ef a | edce ef f | edcd eddf | ff fagg g
eacd c | eac d | eacd c | ac d e | aac d e | aac d
eedc dcdc | dc d | ebc d c | ad d e a | d c eee | d e
dddc b c | eed e | e d d ddcd | c d eede | c d c d | cd a c
c d c d | cd g c | cd cd | cd a c | cd c cccd | de eedc
eea c d e | d d c b c b c e | d e ee | dcd c dd e | cd c eed
cd d eed | cd d eed | c c de | c c de | ccde ccde | d e ed
c e g | cc c c cc | c dd ee | eede c d | c d cd a | c c d | c d cd a
c c d | c d cd a | c cd c | cccd de | c d c d | cd a c | c d cd
There. Of course you'll want to find, or write, some sheet music for these notes so that you can add in rests and dots, and indicate how long the notes should be played in relation to the 4/4 time signature.
If these notes don't work out for you, then try running a Google search on your question. Chances are good that you'll find complete music sheets and performance videos somewhere online. A lot of people who share their music are also willing to share their music sheets, so a quick perusal of YouTube might also be of some help to you. As an added benefit to finding sheet music through YouTube, you'll have an idea of how the song will sound when you play it yourself.
Finally, you can always check your local book or music shop to see if they sell Justin Bieber sheet music books. These books contain multiple songs, so you'll be able to play more of his songs than just Baby.