Melody

Melody in Arab music is usually based on scales or modes known as maqamat. Although many modes have been identified, about a dozen are regularly used.

Tone includes micro-intervals which do not conform with traditional Western systems. Although there are various systems of notation, maqamat are generally treated as scales consisting of 24 equal quarter-tones. Western notation has been adapted, using the "flat" symbol with a horizontal line through it to lower a note by a quarter-tone, and the "sharp" symbol with a single vertical line, to raise it.

Maqamat scales 
(classicalarabicmusic.com)

Melodic modes 
Examples from Lebanon and surrounding countries.

Maqamat
A quick introduction to the maqamat by Adib Chebli.

Rhythm

Rhythms (iqa'at) can be highly complex, with patterns sometimes consisting of as many as 48 beats. The basic components of a rhythm are two kinds of beat and silences (rests). The downbeat (dumm) is a deep sound made by hitting the drum or tambourine near the centre. The upbeat (takk) is a crisper, high-pitched sound made by tapping the rim of the instrument. Players usually ornament the basic pattern with improvisations.

Examples of some common rhythms

Quick reference
Dozens of rhythms

Rhythm generator
Just tell it what you want, and it plays

Playing a percussion instrument
Some simple lessons by Jeff Senn, with special pages on dance rhythms and drums

Drumspeak
A selection of rhythms

Drumspeak
Doum, tek, ka, ba, slap, ruff and snap. Get the right technique.

Music and rhythm
a belly dancer's view, by Roxann (Ann Sabin)

Kesslari's advanced Doumbek rhythms

A "quick and dirty" guide to doumbek rhythms

Part 1: beladi, ayoub, masmoudi (with sound)
Part 2: chifftatelli, kashlimeh, guwazi, chaka
Part 3: falahi, sufi, serto, zar