[quote name='Jazzjames' timestamp='1419163827' post='2637079']
Listening to what Jaco did with 4 strings and 20 frets (i realise he didn't have frets but you know what I mean) .
[/quote]
Jaco had far more fretted than fretless basses but I'm sure you knew that already..
[url="http://www.jacop.net/gear.html"]http://www.jacop.net/gear.html[/url]
in fact, from the article....
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[font=Arial, Helvetica, sans-serif][size=2]1974 acoustic bass guitar [/size][/font]
[font=Arial, Helvetica, sans-serif][size=2]Jaco and luthier Larry Breslin co-designed a fretless, 5-string acoustic bass guitar with a high [i]C [/i]string; upon completion, Jaco paid Breslin $500. It featured a 34"-scale neck with a Brazilian rosewood fingerboard with maple veneer fretmarkers, Brazilian rosewood back and sides and a spruce top. Jaco strung it with Rotosound roundwounds. In later years, the headstock broke off and Jaco brought the bass to Kaufman. He still has it. "[/size][/font]
[size=3][font=Arial, Helvetica, sans-serif]So there you are. if Jaco is the gold standard of bass playing (and he was) then 5 strings are OK.[/font][/size]