I grew up on LI and saw Leslie a number of times in the mid-late 60s pre-Mountain. First with The Vagrants at a teen disco. I remember Leslie having a ripped suit jacket on, amp on a chair and his mother nearby watching him play. The next time I saw The Vagrants they were opening for the Yardbirds at Commack Arena in January of 1968. Still have a copy of The Vagrants single of "Respect", they also were known for their live cover of "Exodus" Later that year I attended his first solo gig with the Lesile West Band, they were on a bill headlined by the Jeff Beck Group with Rod Stewart and Savoy Brown. I was one of many people hiding under the bleachers trying to get away from the excessively loud and shrill volume of Leslie's band which was a guitar/organ/drum trio. He formed Mountain a short time later. I missed their set at Woodstock but saw them later at the Capitol Theater. He had a long career yet Mountain is another band that has been snubbed by the Rock and Roll Hall of Fame...
R.I.P Leslie