Accordion Buying Guide 

Accordions

An accordion  is a portable instrument of the free reed family that uses controlled air blown through bellows to create its sound. The accordionist presses keys (as on a keyboard ) or buttons (in the case of a chromatic accordion) while compressing or expanding the bellows, causing the air to flow past certain reeds, which then vibrate to create the accordion's sound.  Unlike other instruments, there is no standard accordion. For instance, bisonoric accordions play different pitches depending on whether the bellows are compressing or expanding, while unisonoric accordions use the same pitch for both directions. Some are hand-pumped, some are foot-pumped, some are mouth-blown, and some are electronic and have no reeds whatsoever. Thus, your journey into the accordion will be completely and utterly your own.

 As with any instrument, as a beginner it is best to sacrifice quality for affordability, just in case you discover that the accordion is not the instrument for you. 

Piano Accordions
	Piano Accordion  Has a keyboard similar to an organ (as they are both wind instruments) on the right hand, with smaller, lighter keys than an ordinary piano keyboard. The piano accordian has the advantage of a more logical key layout compared to the button or chromatic accordions.

Diatonic or Button Accordions
	Diatonic Accordions  Here the melody-side has a sequence of buttons in three lines, and is limited to fewer keys (sometimes only one). In England it is known as a Melodeon.

Concertinas
	Concertinas  Has buttons arranged in four rows

Chromatic Accordions
	Chromatic Accordion  The melodic buttons are arranged chromatically. This allows greater range and fingering options

Accordions 

http://www.accordions.com/index/gen/lea/gen_lea.shtml

http://www.accordion-o-rama.com/accordions.html

Wikipedia.org