The octave harmonica, which can be recognised by its curved shape, produces a strikingly full sound, which is caused by its double reeds that are tuned an octave apart. As such, the octave harmonica is provided with a double row of holes instead of the single row that we know of the well-known diatonic Richter-tuned harmonica, also known as the blues harp. Unless you block one of the two holes with your tongue, you'll hear a rich, double sound that consists of a basic tone an a higher, 'octaved' tone.
Most octave harmonicas have the same tuning as the blues harp. It is possible to use techniques like overblowing and bending on an octave harmonica, but a Richter-tuned variant is perhaps a better suited instrument for these techniques. Also check out our similar Tremolo Harmonica, Chromatic Harmonica and our Harmonica Accessories.
