Elven Songswords (D&D) | EN World Tabletop RPG News & Reviews
But, as far as I know, there is no specific style or non-standard type of sword used by bladesingers. In DnD elves have always been longsword users, in the sense of DnD longsword, a one handed sword. So any sort of one handed sword that you think elves would wield, traditionally (pre 5E) bladesinging required a longsword, that was their signature weapon.
So bladesingers are mentioned in some 1E FR books, but not much that I know of.
First rules I know of is a 'kit' (thin 'martial tradition' or 'arcane subclass') in 2E, the first pic of a bladesinger I know of is this from 3E Races of Faerun
There's this figure from the 3E miniatures range

Note that the first has a normal looking sword, the figure more of a curved blade
This guy is from the 4E Neverwinter Campaign setting...

...as are the two attachments. Good luck!
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