Rabab, pakhawaj, and rhythmic ankle-bells play the Unstruck (celestial) music, (Guru Arjan)

Saaj is a Punjabi word commonly used to refer to musical Instruments.

Right from the Vedic times, musical instruments were used in India. Ancient sculptures and temples show different kinds of drums, whistles, flutes, harps, gongs, and bells. During the many following centuries, these rough instruments were developed and refined into the forms in which we see them today. Some of the instruments are now decorated with ivory, silver, gold and peacock-feathers. Some of the instruments have facilities for playing delicate gamaks. Musical instruments are made by skilled craftsmen who have knowledge of musical sounds. The important towns where these instruments are manufactured are Lucknow, Rampur, Madras, and Tanjore.

Nowadays, many musical instruments are used, as for example, tampura, sitar, harmonium, veena, sarangi, sarod, been, bansari, flute, tabla, pakhawaj, mridanga, dholak, etc. Some of the instruments are of foreign origin, but Indians have adopted them, as for example harmonium and clarionet. Musical instruments perform one or more of the following functions: (a) to give the rhythm, (b) to provide that tonic note in the form of a drone, and (c) to accompany the vocal music point by point [1]. These instruments can be divided into two categories: svaravad (note instruments), and tal vad (rhythm instruments). The first category of instruments are those which produce svaras (notes) e.g. sitar, sarod, bansari, harmonium, etc. Tal vad includes those instruments which produce rhythm, e.g. tabla, mridanga, pakhawaj, cymbals, etc.

Indian musical instruments are of four kinds:

(1) Tat vad (stringed instruments)
These are instruments with strings. When the strings are touched or played upon, they vibrate and produce different kinds of notes. Tat vad is sometimes called tantra vad. The stringed instruments are of two kinds: tat and vitat.
Tat vad consists of those stringed instruments which are played by fingers directly or with a plectrum, e.g., tanpura, veena, sitar, rabab, been, sur-sringar and sarod.
Vitat vad consists of those stringed instruments which are played with above, e.g., sarangi, dilruba, taoos, and asraj.

(2) Sushir vad (wind instruments)
This covers instruments in which notes are produced by air columns. In such instruments, either the air is blown with the mouth as for example bansari, clarionet, shenai, flute, or through the bellows as in harmonium and organ.

(3) Avanad vad (leather or percussion instruments)
These are percussion instruments which produce sound when dried animal skins, tightened by leather braces or cotton straps are struck. Mostly such instruments are used for producing tals (rhythms) and that is why some people call them tal vad. This category includes mridanga, tabla, pakhawaj, dholak, nagara, dhadh, kanjira, and damru.

(4) Ghan vad (idiophones).
These are idiophones of self-sounding instruments which combine the properties of vibrator and resonator. Some of them are struck together as cymbals, clappers and khartal, while some are struck singly as bells, gong, chimta (a pair of tongs) and jaltarang (cups of water producing different notes). Some are shaken like rattles and manjira. These instruments are made of wood or metal or both. In addition there are earthen pots like matka or ghatam. Some of these instruments are useful for rhythm only, e.g., manjira, jhanjh, and khartal.

As mentioned above, tat vad, sushir vad, and partly ghan vad come under the category of svara vad, as for example tanpura, sitar, bela, sarod, bansari, shehnai, harmonium, organ, piano and jaltarang. Avanad vad and partly Ghan vad come under the category of tal vad, e.g., mridanga, tabla, pakhawaj, damru, manjira, khartal and jhanjh.