Watch the Basic Left Hand Technique online guitar lesson by John Goldsby from Upright Bass Handbook
There are a couple of big differences between the double bass and electric bass guitar: The double bass has no frets, and the string length on the double bass is much greater than the string length on the electric bass. A typical Fender-style jazz bass has a string length of about 34 inches, or about 86 centimeters. A typical acoustic bass might have a string length of 42 inches, which is about 106 centimeters.
This huge difference in string length means that on the acoustic bass (the double bass) we need to use different fingerings than what we might use on the electric. When fingering the double bass, we use first, second, and fourth fingers of the left hand. These fingers are indicated on the written notation with the numbers 1, 2, and 4. The third and fourth fingers work together to press down notes in the lower positions.
In the very highest positions on the bass--the thumb position--we'll use the third finger instead of the fourth, but only in the very highest positions. In the lower positions, you have to use first, second, and fourth fingers. There's no way around it, and I can't stress enough the importance of starting with the correct fingering technique with the left hand. There are other double bass fingering systems (Rabbath, Vance, Billé, Suzuki), but Simandl's 1-2-4 guideline is an historically accepted system that all bassists acknowledge.
Now let's find some of the notes in the lower positions on the bass. The very first position, just above the nut, is called "half position." On the G string, the first note above the open string is an Ab, played with the first finger. The next note is an A, played with the second finger. The top note is a Bb, played with the fourth finger. Note my left hand position on the video: When I play one note, all of my other fingers are positioned just above the string, ready to play another note. I think of my left hand position like I'm holding a glass of water: the thumb is opposing the second finger, and all four fingers are helping hold the glass. Nothing is tightly squeezing, and there is just enough pressure to keep the glass in my hand.
Pay close attention to the fingerings of the notes in half and first position on all four strings. If you have a solid grasp of these fingerings in the low-position "money notes," then you're well on your way to solid upright bass technique.
For the final exercise in this lesson, let's go up the G string and find the note D. We're going to play the notes A and B in the first position, and then make one shift up the neck to play the notes C and D. The note D is the same spot where we find the high D harmonic which we use to tune the bass. We're also going to use this note D to play the etude in the next lesson, "Let's Get Funky in D"!