I was re-reading the new translation from over at the USCCB site last night. There seems to be absolutely no provision for the Gradual to be sung. It only mentioned a psalm... could it be assumed that a Gradual would fall into that category? It certainly doesn't seem to give it 'pride of place'.
from p. 9 of the OrdoMissae WhiteBook pdf.:
11. The psalmist or cantor sings or says the Psalm, with the people making the response.
from p. 9 of the OrdoMissae WhiteBook pdf.:
11. The psalmist or cantor sings or says the Psalm, with the people making the response.