2.Tangga pentatonic

Pentatonic is derived from a combination of words penta (five) and tonic (tones), so tangganada pentatonic can be interpreted as consisting of five tones. From diatonik major scales (c - d - e - f - g - a - b - c ') the amount of 7 tones, pentatonic scales can be obtained by subtracting the two tones, in this case there are two kinds of pentatonic scales: 1. c - d - e - g - a - c '(without the f and b) 2. c - e - f - g - b - c '(without the d and a) generally pentatonic Scales used in traditional music (China, Japan), including the Indonesian gamelan (Javanese). Especially in the Javanese gamelan, two kinds of pentatonic scales is called the barrel bridge and the bridge barrel slendro pelog

tone following the ladder structure;

1) Oriental (China / Japan)
... 1-2-3-5-6 ...

In China, scales, tone 4 (fa) and the tone 7 (si) is removed to form the structure of distance

1-1-1? -1

2) Pelog (gamelan)
... 1-3-4-5-7 ...

Gamelan scales are scales used in the Java community, which removes the tone 2 (re) and 6 (la) and established the range 2 -? -1-2
3) Slendro (gamelan)
... 1-2-4-5-6 ...

In slendro, which eliminated the  tone 3 (mi) and 7 (si) to form the structure of distance

1-1? -1-1