pentatonen.

1876 J. Stainer & W. A. Barrett Dict. Musical Terms 347/2 Pentatone, an interval of five whole tones, an augmented sixth.

1885 Jrnl. Soc. Arts 33 526/2 The first system seems to be formed by taking the Fourth flat enough to give, practically, a division of the Octaves into five equal Pentatones.

1986 Amer. Jrnl. Philol. 107 462 There is not one dia tessaron (‘fourth’) or dia pason, let alone a tritone, tetratone, pentatone,..to be found between two consecutive notes.

2001 New Grove Dict. Music (Electronic ed.) at Jacobus of Liège In addition to the usual consonances and their compounds Jacobus also treated the comma, diesis, apotome—and intervals such as the tetratone, the pentatone..and the hexatone.