The maqams (Arabic for position) can be called scales or modes and are common in music from the Middle East and in Turkish Ottoman classical music ("Makam" can be translated to scales or modes in Turkish). One of the things that distinguish a maqam from a scale is that a maqam sometimes uses quarter tones (a pitch between two semi-notes, such as a tone between F# and G).

There are lots of maqams which are organized into several groups and sometimes hard to grasp at the first moment. The scale illustrations below will give you an introduction to Arabic maqams. As you can see, the scales in different keys also have specific names. Maqams often begins on C, D, Eb (quarter-flat), F, G, A or Bb (quarter-flat).

C (Hijaz Kar Maqam)

C Hijaz Kar Maqam scale diagram
Notes: C, Db, E, F, G, Ab, B, C

D (Shahnaz)

D Shahnaz scale diagram
Notes: D, Eb, F#, G, A, Bb, C#, D

Eb (Maqam Mustar)

Eb Maqam Mustar scale diagram
Notes: Eb, F#, G, A, Bb, C, D, Eb

F (Maqam Jiharkah)

F Maqam Jiharkah scale diagram
Notes: F, G, A, Bb, C, D, Eb, F

G (Shadd Araban)

G Shadd Araban scale diagram
Notes: G, Ab, B, C, D, Eb, F#, G

A (Suzidil)

A Suzidil scale diagram
Notes: A, Bb, C#, D, E, F, G#, A

Bb (Ajam Maqam)

Bb Ajam Maqam scale diagram
Notes: Bb, C, D, Eb, F, G, A#, Bb

As you can see, the intervals differ in the scales above. The interval steps with quarter tones are written as 3/4. For example, in Eb (Maqam Mustar) the intervals are: 3/4 - 1 - 3/4 - 3/4 - 1 - 1 - 3/4. can be recommended for further reading.