Hohner 2509 Echo Harmonica, Minor C by Hohner. $95.00. Hohner's tremolo harmonicas are double reed instruments. The bottom row of holes features the same notes as the top row, tuned slightly higher. This special tuning creates the tremolo's distinct sound, a beautiful vibrato effect with a richer tone. These harmonicas are primarily used in ballads, folk, reggae & gospel music.. Save 30% Off!