The garmon

The garmon is a Russian free reed instrument of the same type as an accordeon. Its name comes from the Russian word "garmonika" which means "harmonics". The garmon has two rows of buttons at the right side, which play the notes of a diatonic scale. At the left side a garmon has at least two rows of buttons, which play the primary chord in the key of the instrument as well as its relative harmonic minor key. Many instruments do have additional buttons at the right side with usefull accidental notes.
Some instruments do also have additional buttons at the left hand, for playing in related keys, and a row of free bass buttons, for facilitating the playing of a bass melody.
There are two major classes of garmons: the unisonoric (plays the same note while pushing or pulling the bellows) and the bisonoric (plays a different note while pushing or pulling the bellows).
Of the unisonoric type are the "livenka" (after Livny, Oryd Oblast) and the "khromka" (chromatic).
Bisonoric garmons are the tula accordeon (after Tula) and the "talyanka" (Italian).
The garmon is usualy played in Caucasian and Volgian folk music.
The standard arrangement of a garmon is known as a "25 x 25" and contains:
  • 25 treble buttons in two rows: three diatonic octaves and three accidentals
  • 25 bass buttons in three rows: two rows of eight buttons, with bass notes and chords, one free bass row.
The arrangement of the treble keyboard allows the musician to play a scale, alternating between the two rows. The three accidental notes are arranged so as to mirror the position of the left-hand chords that contain them.
The bass keyboard: the principal chords for the major key are in the outer row, placed in circle of fifths order. The principal chords for the harmonic minor key are in the middle row. The free bass notes are in the inner row, including one free accidental bass note.

During the 19th and 20th century Russian masters invented a lot of different types of local garmons:
  • Tula garmon: it was the first Russian accordeon, manufactured since 1830, with five or seven buttons at the right keyboard and two at the left. It had two full diatonic actaves
  • Khromka: invented in 1870 in Tula by the Russian musician Beloborodov. It was an unisonoric diatonic instrument, with on the right keyboard also two or three chromatic buttons. It became the most popular button accordeon in Russia, which means that almost all modern Russian garmons are khromkas.
  • Vyatka garmon: appeared in the middle of the 19th century on the factories of Vyatka governorate. It was a chromatic unisonoric instrument with a piano keyboard on the right side and two bass buttons on the left. It was the prototype for many different types of national accordeons in the Volga region and the Caucasus. After this instrument Russian chromatic and diatonic accordeons called "royal" were made. ("Royal" in Russian is a grand piano)
  • Saratov garmon: a diatonic bisonoric garmoshka with the sound of a ringing bell after each pressure on the accompanement keys. Click the link to hear the saratov garmon
  • Livenka: livenskaya garmoshka, developed during the years 1860 - 1870 around Livny
The tula, vyatka and khromka were the basic instruments for almost all the national Russian and Soviet garmons. But sometimes modifications were needed to fit the local national musical traditions. 
Volgian
  • tatar accordeon: diatonic pianoaccordeon, based on the vyatka garmon, with 12 piano buttons on the right and three basses on the left or 16 piono buttons on the right and 12 basses on the left.
  • mari accordeon (maria garmon): a seven-button diatonic bisonoric accordeon based on the tula garmon.
  • mari koga garmon and chuvash kubos: based on the khromka
North Caucasian
  • komuz: a piano diatonic accordeon based on the vyatka accordeon. It is the main instrument of folk music in the Caucasus.
Oriental accordeon
The oriental bayan was invented in 1936 in the Kazan musical factory. It has a piano keyboard at the right, which is a little smaller. Since 1961 the left keyboard mirrors the right one, though these buttons are not rectangular, but round as the buttons of a button accordeon. This type of instrument is popular in the music of Azerbaijan.

Georgian

  • Garmoni: came from Russia, in the 1830s and is popular in Tusheti as an accompanying and solo instrument. 
  • Buzika: a kind of small accordeon, wide-spread among the mountain inhabitants.
  • Tsiko-tsiko: came to Georgia from Europe
Sources:
http://en.wikipedia.org/wiki/Garmon
http://anyonemusic.blogspot.be/2008/03/accordions.html
http://www.barynya.com/garmoshka.stm