An oboe-bassoon-piano trio is a chamber music ensemble made up of one oboe, one bassoon, and one piano, or the name of a piece written for such a group. The ensemble is similar to the classical piano trio in which the violin is replaced by the oboe and the cello is replaced by the bassoon. The similarity of the oboe and bassoon stem from their relation as members of the double-reed woodwind trio. Professional trios such as the Poulenc Trio are very rare, but the literature for the group is often performed by ad hoc groups.