The Richter-tuned harmonica, or 10-hole harmonica or blues harp, is the most widely known type of harmonica. It is a variety of diatonic harmonica, with ten holes which offer the player 19 notes in a three-octave range.

Alex or Aleck Miller, known later in his career as Sonny Boy Williamson, was an American blues harmonica player, singer and songwriter. He was an early and influential blues harp stylist who recorded successfully in the 1950s and 1960s. Miller used various names, including Rice Miller and Little Boy Blue, before calling himself Sonny Boy Williamson, which was also the name of a popular Chicago blues singer and harmonica player. To distinguish the two, Miller has been referred to as Sonny Boy Williamson II.