Why are there different numbers of strings?
Basses most often come in 4-, 5-, and 6-string models. Though, any number of strings is possible.
The first electric basses to be produced came with 4 strings. For many years that’s all there was and that’s all people felt they needed. A lot of music has been played on 4-strings.
The reason for having more strings is to add more range to the bass. More range means being able to play more lower pitched notes and/or higher pitched notes. Also, the more strings you have under your fingers, the more notes you have under your fingers. With more strings you don’t have to shift around the neck of the bass as much.
The popularity of 5- and 6-string basses exploded in the 80’s. A couple of things caused this to happen. First, bassists in the 80’s were competing with electronic keyboards. Many bassists were being replaced by computers and keyboards because they could play lower bass notes than a standard 4-string bass. To compensate, some bassists began playing 5-string basses that added 5 lower-pitched notes to their arsenal.
Secondly, a number of amazing bass players in the 70’s took the electric bass to new heights. Bassists like Stanley Clarke, Jaco Pastorius and Jeff Berlin showed the world electric bass players could really solo and play a melodic role, too. With this new frontier for bass players opened up, bassists wanted more range to play solos in. By adding another string, a 6th string, on the high end of the bass, bassists could reach higher notes more comfortably.
Are more strings harder to play?
There is definitely more to control and keep track of as you add more strings. Beginners don’t often realize there is a lot of work in keeping the bass strings quiet in addition to getting the notes to ring out. The more strings there are, the more there is to keep quiet.
Also, the strings get closer together making some playing styles (e.g. slap bass) a little trickier. You have to be more accurate. And, the neck gets wider. That means more reaching and stretching on the neck of the bass. Regardless of what you choose, there’s going to be work and practice involved. And, you can always switch later on. It’s not that hard to go from one to another.
How many strings should you get?
The 4-string bass has been around the longest and a lot of music has been played on it. For most people a 4-string bass is adequate if not perfect for them. Why get more strings if you’re not going to use them?
It is possible to tune a 4-string bass lower than its standard tuning and it is very common to do so. You can tune it lower by 2 or 3 notes if you need those lower pitches from time to time. Since it is not designed to be tuned that low, you might not get the best sound or playability by tuning a 4-string bass lower, but it is an option.
For most styles you’ll probably be ok with a 4-string. If you’re into heavier music that’s popular today, you may want a 5-string bass where you can reach those lower notes without having to detune your bass.
I think it’s better and easier for you to learn to play in a standard tuning with an extra string rather than some alternate tuning on a bass with fewer strings. If you need those low notes a lot, you should consider a 5-string.
An alternative to getting a 5-string bass would be to get a 4-string bass and string it like the lowest 4 strings of a 5-string bass. Some manufacturers are designing basses like this now. It would be tuned BEAD, instead of the standard 4-string bass tuning EADG.
If you are buying your first bass, you probably don’t want a 6-string bass. It’s overkill. And, in the beginning you should probably focus on playing the traditional role of the bass anyway. That means playing the lower notes more often. You can save the 6-string for your second or maybe third bass if you find you need one.