Tibetan alphabet is a kind of abugida where glyphs may combine into new different forms, taking different positions in their combinations according to their types (see H.B. Hannah, pp. 16- 45).
Each glyph has an initial tone, either high or low, which, in turn, may be changed depending on an subjoining glyph, thus making from three to five or four tones altogether.
Moreover, the thirty initial glyhps are grouped, according to classical Tibetan grammar, into five genders: Masculine, Common, Feminine, Very Feminine, Barren and Neuter (see H. B. Hannah).
While classical Tibetan grammar is more or less unanimous, the dialects of Tibetan vary to a great extent and may even have no tone distinction (as it is the case with the dialect of Amdo).
Hence, the questions are:
Do Tibetan tones also have gender properties, or is this a property of the glyphs only?
Do the gender property of the tones and/or that of the glyhps change under tone sandhi they undergo when (sub)joined with other glyphs?
(For the tone sandhi, please see the data by Sun Kuo-ming and Sun Duanmu as generously provided by Gaston Ümlaut)