. . we know Jaco for mostly playing at or near the bridge pickup, with a strong midrange. I don't consider this tone so much a product of his gear as much as his technique. Give me a Jazz bass, a fretless Ken Smith, an ACG or a Modulus Quantum and I will reproduce that tone for you in a roundabout fashion through technique alone. .
Essentially, Jaco unlocked a new way of playing the bass and I don't think the raft of bassists that arrived in his wake as being derivative for seeking that same sound. . Jaco wasn't just defined by his tone though, his notes and phrasing gave him away too, moreso than his tone ever did. . His resolutions, the patterns his hands took to, even the canned licks that he could transpose to different keys to play over a given chord, were all trademarks of his style.
Jaco is credited for pioneering a distinctive sound. The sound is so profound that anyone that reproduces the sound is considered a Jaco counterfeiter. However, his sound is more than just the physical sound of his fretless bass. It is rhythm, sense of bass, harmony, improvisation, and instrument proficiency and technique.
Although many can achieve Jaco's distinctive tone, few can achieve his level and style of playing. Many tribute recordings have been made and none surpass the master. Jaco's musical artistry is that strong.
Bass players that catch flack for enjoying and using Jaco's tone are done great disservice. Once a certain tone is invented it belongs to the world. Those that argue to the contrary are disingenuous and shallow. For example, take the sound of a Hammond B-3 organ. It is a staple in rock, gospel, and jazz, having a distinct tone with many followers. Throw in the sound of some floating Leslies, and the B-3 sound is remarkable and identifiable. The differentiating factor is always the player. As there are thousand of B-3 players that find their own voice in the world of B-3, so it can be with "Jaco tone" electric fretless bass. The exact premise also applies to Fender Rhodes, traditional instruments in general (trumpet, saxophone, piano etc), and virtually any instrument.
I hear few criticisms of players that play and love Precision basses as being James Jamerson wannabees or clones. That tonal signature gets plenty of love and respect by many. Rightfully so. The distinct tone signature of the fretted Jazz bass gets similar respect. Rightfully so, again. Pull the frets out of the same Jazz bass and it becomes Jaco tone, disrespected and disdained by many.
However, the fretless tone that Jaco pioneered is truly a delicious color of the rainbow. May its practitioners nurture it, and handle with love and care. Be brave and develop your voice using Jaco's invented tone. Jaco will be proud!