Or should I say lack of concentration. I know about 50 songs fairly well (all the ones in my band's setlist and a few others) and I can easily play all of them without making mistakes.. technically speaking. The problems occur when my mind drifts and suddenly oops.. there's a mistake. It happens way too often for my liking.

My bandmates say I am just being too hard on myself, but if I know the stuff why do I still make silly mistakes?

Do you have the songs memorized?

Here's something interesting to think about:

Ideally you want to play from the right side of your brain (the creative side) as much as possible. Unfortunately the left side of your brain tends to dominate the right side, so a lot of times we'll be playing with our right brain (and practicing, too, further encouraging this). Therefore, when our mind wanders, we lose track of the music. If you have a hard time carrying out a normal, relaxed conversation with someone while you're playing, that's a sign that you're playing from your left brain too much.

One trick (I think Liszt used this with his piano students) is to read a book while you practiced, or some other activity that will occupy your left brain. This way you get used to playing with from your right brain.

Regarding technical mistakes, sometimes it's because you're playing a little too much. It's often a good idea to play less anyway. I'd like to note that it's also very important that you not let any technical mistakes derail you from the flow between your ears and what you play.

I also advise you not to get stuck in the trap of fearing making mistakes. It's strange, but I've found that when I don't care about making mistakes I usually don't make them. :)

Well, hope you were able to find something useful in all this.

Take care!

Something that helps keep me concentrated on my music is to not think about what I'm playing as a written down song. First go through one of your tunes and figure out all the chord changes. next time you reherse with your band instead of playing the song verbatim, completely from memory try playing the maing bassline once or twice and then change it up a little bit. Make sure you still accent all the important notes, but throw some new stuff in. If you start to play more based on the changes than on whats been written down I think you'll be able to concentrate better, You'll enjoy playing more, and songs your band covers will have their own feel instead of feeling like it did on the album. This is how I personally enjoy to play, and I think you should give it a try if it interests you, it makes playing music much more enjoyable for me.

Enjoy what you play, get into your music, and you wont make mistakes like that.

Being 'where you are at when you are there' is the trick.

What I mean is taking steps to consciously tell yourself, "I am playing this song. It is fun and I enjoy it. I don't need to think of other things - only playing this song and having the best time I can while I am playing this song."

You don't have to 'run the chords' in your head. If you don't know them now, you are not going to teach yourself them in the seconds before you play. Just say to yourself that you are focusing all your energy on playing the song to the best of your ability, relax and enjoy yourself.

Sounds simplistic but it helps remind you that your mind should not be concerned with 'other things'. Doing nothing leaves the possibility wide open that you may start thinking of other things. The only thing you are there to do it jam on your song. If you can go 'inside' and live it - become one with the idea - you stand much more of a chance to really play the song without being interrupted by 'stray thoughts'. You can enjoy the act of playing the song much more because you are focused and not distracted.

But also know that you are human and the thing that make you human is fallibility. If you were infallible, well, that would imply you are perfect. But there are conscious steps you can take to 'orient' or 'center' yourself in all activities - so taking a conscious step to tell yourself to be where you are while you are there can go a long way to ensuring you are focused.

Finally, and I don't mean to imply anything, but there is a thread here about bass players with ADD and AD/HD (http://www.talkbass.com/forum/showthread.php?t=239895&highlight=ADD+AD%2FHD). One of the symptoms of those conditions is being constantly interrupted by 'stray thoughts'. I am not suggesting that you have ADD or AD/HD, but if you find that being constantly distracted is something that you experience in areas other then playing music, you may want to look into being tested.