Cross Harp MS Harmonica - Key of C. For 150 years, Hohner's diatonic harmonicas set the industry standard through high quality construction, excellent response and unsurpassed tone. Often called Blues Harps, they remain a fixture in blues, rock, country, folk, and many other styles of music. Traditional Richter tuning and undivided air channels allow for techniques such as bending and overblowing reeds, creating the signature wailing sound typical of the harmonica. The gold plated plastic comb, black Greblon coated covers and extra thick (1.05 mm) reed plates make the Cross Harp a stylish model with a big sound.