The most important thing to know when you're lost is that the wrong note at the right time is far better than the right note at the wrong time. Even if you're lost, keep playing something with the right timing - people in the audience won't notice a wrong note or two as much as if the bass drops out or you lose the feel.
I also posit that there's never really such a thing as a wrong note - it's all timing errors. That note you just played (that you don't think was a good note) is absolutely a good note. If it didn't fit there, it will, if you play it at the right time. The next measure, the next song, the next week - there's some time when that note is perfect.
I also posit that there's never really such a thing as a wrong note - it's all timing errors. That note you just played (that you don't think was a good note) is absolutely a good note. If it didn't fit there, it will, if you play it at the right time. The next measure, the next song, the next week - there's some time when that note is perfect.