Wikipedia
Merukhand is an improvisational style in Hindustani classical music involving permutations of a fixed set of swaras or notes (meru, axis or skeleton) broken up in various ways (khand, fragment), while retaining the proper emphasis on various notes as required by the raga.
Merukhand techniques were developed within the Bhendibazar gharana and popularized by masters like Aman Ali Khan and Abdul Waheed Khan. In the mid-1950s, they were adopted by the eclectic Amir Khan in his own badhat (progression), although he did not use pure merukhand but inserted merukhandi passages into his performance. His disciple Thomas Ross says of this permutational style that
improvisational forays treating merely three or four notes may occupy twenty minutes or more.Merukhand is now a part of the improvisational strategy within the Indore gharana founded by Amir Khan
"Merukhand" Gayaki In Music Practice Merukhand Gayaki plays a vital role in the frequent practices and even in the performances. Ustad Amir Khan Saheb's Gayaki is always associated with merukhand style, because he often created the raga progressions through this technique, during his recitals, which is why his vocalization was unique and mesmerizing.
In merukhand, 3 or 4 notes patterns are selected and all the possible combinations and patterns are rendered while practices. Merukhand technique works well in enhancing creativity of a singer and in improving the vocalization of jumped notes as well.
To illustrate the merukhand style, let's select 4-note swar pattern initially:
Sa Re Ga Ma
Now we will create all the possible pattern, taking only these notes, without repeating any swaras:
Sa Re Ga Ma Re Sa Ga Ma Ga Re Sa Ma Ma Ga Re Sa Sa Re Ma Ga Re Ga Sa Ma Ga Re Ma Sa Ma Ga Sa Re Sa Ga Re Ma Re Sa Ma Ga Ga Sa Re Ma Ma Re Ga Sa Sa Ga Ma Re Re Ga Ma Sa Ga Sa Ma Re Ma Re Sa Ga Sa Ma Re Ga Re Ma Ga Sa Ga Ma Sa Re Ma Sa Re Ga Sa Ma Ga Re Re Ma Sa Ga Ga Ma Re Sa Ma Sa Ga Re = 24 patterns.
Furthermore, "Pa Dha Ni Sa", "Re Ga Ma Pa" etc. note series also makes 24 possible improvisational patterns. We can see that numerous swar-patterns can be created twisting only four notes.
Specific notes of the ragas can also be practiced for hours, as it keeps the brain engaged in creating phrases. Often, we come to miss some of the patterns. But this is beneficial exercise for amateurs and professionals too. We can take the same pattern to make the Bhairav notes, making Re Komal (flat): Sa Re Ga Ma OR Kafi notes: Sa Re Ga Ma (Ga Komal). , OR Yaman notes: Ni Re Ga Ma (Ma teevra or sharp).
Now we will create the merukhand pattern taking five notes, of Bhoopali raga: S R G P Dh
Sa Re Ga Pa Dha Saa, Saa Dha Pa Ga Re Sa
SRGPD SRGDP SRPGD SRPDG SRDGP SRDPG
SGRPD SGRDP SGPDR SGPRD SGDPR SGDRP
SPRGD SPRDG SPGRD SPGDR SGDRP SGDPR
SDPGR SDPRG SDGRP SDGPR SDRPG SDRGP
RSGPD RSGDP RSPGD RSPDG REDGP RSDPG
GSRPD GSRDP GSPDR GSPRD GSDPR GSDRP
PSRGD PSRDG PSGRD PSGDR PSDRG PSDGR......
There may be more patterns which I have missed out. The idea is that merukhand requires a lot of thinkable and creative brain. As the same time, it takes hours to vocalize each pattern separately with accuracy. For example: SPRDG i.e., Sa-Pa-Re-Dh-Ga pattern looks simple 5 notes, but all these skipped notes might make one crazy during unfolding these tunes.
Initially, merukhand technique requires perseverance, patience and practice, but at last, one can easily be pertinent in improvising the ragas, even in the advanced level. One can attain unhesitating command on rendering taans with absolute variety and fluency, after working on this stylization.