Depends on the range you're 'vocaling' in.
Bass and also tenor clef.
Bass clef.
bass clef
The majority of any score written for bass guitar will use a bass clef. Very rarely will it be anything else.
Treble
Bass and also tenor clef.
His vocals would certainly be using treble clef. Most singer's vocals remain in treble cleff range (with the exception of very deep baritone singers). The bass lines would be in bass clef because they are much lower notes (like the catchy part of Billie Jean, for just one example).
Bass clef.
bass clef
The piano uses both the Treble clef (for higher pitches) and the Bass clef (for lower pitches). It plays in the key of C. Sometimes it is misinterpreted that the Treble clef is for the rigth hand and the Bass clef if for the left hand. This isn't true. Both hands can use the Treble clef or Bass clef, or even the right hand can use the Bass clef and the left hand can use the Treble clef.
The majority of any score written for bass guitar will use a bass clef. Very rarely will it be anything else.
The piano uses both the treble clef and the bass clef.
It's "Clef" No "T." Bass clef.
Bass Clef. This is to make it easier to read as if it was in treble clef there would be loads of sub-line below the stave.
bass clef
Bass claf
Treble