The Thunderbird was low and loud. Just how I like it! The mahogany body with the walnut neck through made for good sustain. Unfortunately, the tone of the Thunderbird didn't end up matching Micheals (McDonald) keyboard. When a piano player is playing the bass notes with his left hand, they don't sound super low. You can hear the notes clearly all the way down to the bottom, but with the Thunderbird I couldn't do that because it would mask what Mike was playing with his left hand. I cut my hands so much on the Thunderbird bridge that after the fall tour of 1975 I moved on to another bass. I switched it out and went to the Precision and my custom Jazz bass. Both of these basses sounded finer and fit Mike's keyboard playing much better!

“A lot of times with bass, what the bass player plays is really what the chord becomes. With the Doobies we all kind of came from that background of which we were playing chords that were a little more sophisticated sounding, but we didn't really know what they were, other than it was a C over G or a B flat over C. My point being, it was always the bass notes that dictated the feeling of the chord. Whether it was a dominant chord, a four chord or a five chord.. it's about where you put the bass note. The lowest note that made that chord has the characteristic it was going to have. I always wanted the bass player to play the note that was going to best represent the chord that I was trying to play in the song. Tiran understood in advance where I was going and he would already be there. But there were times too when he preferred to play something different and it wasn't always, to my thinking, the best choice. But he would persevere. We didn't always agree, but I would say I probably deferred to his thinking more times than not. Because later on I would start to see or hear what he was going for, in a much clearer way. He would be on his way to the chord that I was already hearing and he was just playing a different note to get there. It might defer the chord feeling, but typically I wound up liking that more.” - Michael McDonald