How to Start Grooving....

        So your guitar player says "hey man lets jam... here is a riff in E".  You listen to the riff but have no idea what to play.  Have you ever been in that situation?  I know I have.  Or maybe the worship leader at your church wants to go into a impromtute jam and extend the song or break it down and go into a ambient worship moment.  How do you come up with something to play while in the moment.  Maybe you are in the studio and the producer wants you to play something different than what you worked on all week.  These are situations all bass players will face at some time or another.
        So how can you get into a groove with a band if they start to improv a riff?  Thats a great question so lets break this concept down.  First off remember you need to get back to one, or the downbeat.  Everyone depends on that downbeat to hold a improv together.  If you do not know the minor pentatonic scales you need to learn then inside and out.  Minor pentatonic scales can be a foundation for you to create a groove on the fly.  If you do not know the major scales you need to learn them inside and out.  Major scales will give you tools to be melodic.  This is important for bass players that play at their church. 
        Once you learn the open E minor pentatonic scale make open E your downbeat.  Here is the scale:

                E (OPEN E)  G    A   B   D   E (octave E 7th fret A string)   G   A   B   D   E
  Fingers:  open               1    1    3   1    3                                             1    1   3    1   3

This is in a open position and is a good place to start.  make open E your downbeat of one and play around with it.  Notice how many notes are played on the 5th and 7th frets.  This is what I call the "Box".  Groove in the box and get to open E for your downbeat. 
         Closed position minor pentatonic scale is needed as well.  Start this scale on the minor 7th scale degree.  For example, if you want to play a G minor pentatonic start on the F two frets down.  So the pattern would be this:

              F     G (this is your root of the scale)     Bb     C     D     F     G (octave)     Bb     C
Fingers:  1      4                                                  1        1      4     1      4                   1       4

So G is the root of the scale even though you start on the F.  Just like the open box scale having several notes on the 5th and 7th frets the closed position has a similar pattern.  In this particular position look at how many notes you can play on the 3rd and 5th frets. Same concept as the open box... make G your downbeat and groove in the box.  you will get the hang of it.  The closed box scale position you can move anywhere on the neck.  For example, if some one says lets do a jam in A...where would you groove your box?  G would be the first note of the scale and A would be the root and your box would be on the 5th and 7th frets.  What about C?  C would be the root and your box would be the 8th and 10th frets.  Give it a try and email me with any questions.
      Here is a live video of me playing a song I wrote called Neurosis... it uses the Open box scale in E and A throughout the song.  Now also remember this not the only scale to use to create grooves and improv grooves with.  Next time I will talk about how to create a groove using these scales.  Peace out !