Was taught the utter basics in the mid-1970's by a jazz guitar prodigy middle school classmate who needed a bass in his garage band. Took a couple lessons from his family friend, the late great Harry Leahey (https://en.wikipedia.org/wiki/Harry_Leahey), unfortunately those didn't "stick". Everything else was self-taught, starting with ear training using a stack of 70's rock LPs (primarily Chicago albums 1 through 5), a Zenith portable record player and >thousands< of needle-drops.