Ranganayaki,
No there's no justification in linking the instrument played by Shrinivas to the acoustic mandolin. Much hilarious and ridiculously uninformed ink, as is only possible in the carnatic world, has been spilled linking Shrinivas to the "transformation of the Italian folk insturment" into a vehicle of Carnatic gamakams
. A small number of people who actually know about instruments know that the acoustic mandolin is
particularly unsuited to playing any kind of gamakams. The frets are waaay too high to effect any kind of sliding motion over the strings.
The height of the frets (i.e., how much relief they have over the underlying fretboard) bear some explaining. They are directly responsible for whether or not we can effect a sliding motion called gamakam over the strings. The acoustic mandolin has the highest frets. Next comes the acoustic guitar, definitely a step lower than the acoustic mandolin. Therefore some reasonable sliding motion can be effected over them. The electric versions, both for guitar and mandolin, have extremely short frets, mere bumps over the fretboard. This is the key feature which enables the ability to slide over them and play gamakams. And of course, the unlimited sustain offered by the amplification via pick up ensures that the slides are audible. One doesn't even have to press the string down on the fret to be audible. This is the key to the perception of "continuity" while sliding on a fretted instrument.
It may also be worthwhile to point out that unlike the vina, there is no pulling of the strings in the Carnatic guitar/mandolin playing technique. In this sense it is more like the violin or chitravina. What is ironical is that in rock music and blues music, they do pull on the electric guitar strings a little to effect the typical wailing bending of the notes.
Electric mandolins come in different varieties, from a hollow body to the solid body, and can have 5 or 8 strings (typically 4 pairs, as in the acoustic mandolin). The instrument played by Shrinivas is the
"solid body electric mandolin", practically an electric guitar. It relies entirely on the amplifier pick up exactly like the electric guitar.
As regards the differences:
a) Electric mandolin is smaller in size, i.e., the fretboard is probably 60-70% the length of a standard electric guitar. This makes it easier to play rapid fire passages of melody but much more cramped for playing chords (which are not needed in Carnatic music).
b) Electric mandolin used by Shrinivas had the facility for up to 8 strings, whereas the lead guitar usually has only 6 strings (OK, there's something called the BASS guitar, with 4 very thick strings, which is not relevant to the discussion). Out of the 8 possible strings, Shrinivas used only 5, leaving the other tuning keys as dummies (i.e., only five strings were actually "strung" on the instrument).
In western music, the solid body electric mandolin has a very very limited use, since the solid body electric guitar is more versatile due to its tuning and the ability to play leads and chords. In a peculiar way, Shrinivas was the best vehicle in the world for this instrument !
UPDATE:
I saw some more photos of Shrinivas' "mandolin", including the one above, and it turns out that in recent times, he's discarded the older modified 8 string version to a modified 6 string version. In either case, the insrtument is strung with only 5 strings but in the older case there were three dummy tuning keys, while in the newer ones there's only one.
