Reference Pitch Sources You Can Use to Tune Your Bass Guitar When Playing Alone
When you're playing alone, it doesn't matter whether you're bass guitar is in tune with the rest of the universe, but you do need to have all your strings in tune with each other if you want your music to sound harmonious. You can use any of the following sources to tune your bass.
Using an electronic tuner is by far the easiest way to tune your bass. The modern tuners have a display that lets you see exactly where your string is, in terms of pitch, whether it's sharp (too high) or flat (too low), and what note it's closest to (in case your bass gets knocked around, and the G string is now closer in sound to F than G).
To get your bass into tune with a tuner, follow these steps:
Buy a tuner.
Okay, okay! Maybe that goes without saying, but keep in mind that you want to use a tuner that can register the low bass frequencies. Not all tuners can hear bass notes. You can get a tuner that connects to your bass via a cable, or you can get a clip-on tuner.
Plug your bass into the tuner via the cable (an electric cord that connects your bass to your amplifier) or clip the clip-on tuner onto your headstock.
Strike an open string and let it ring.
Low frequencies travel slowly, and the tuner needs time to read the note.
Tune the string until the needle (or light) of the tuner is in the middle of the display, indicating that the string is in tune.
Make sure to check that the pitch indicator shows the correct note for the string (E, A, D, G), or you may find that the G string is in perfect tune with G♯, which is way out of tune with what the G string is supposed to sound like.
Tuning with a tuner works even when you're in a noisy environment. Make sure you have a spare battery for your tuner, though. Otherwise, the only way you can see motion in the tuner's needle is by watching it jump as you fling it against the wall in frustration.
You don't want to depend entirely on a mechanical device. You need to know how to tune the bass by yourself in case a garbage truck backs up and crushes your tuner as you're loading your gear into your car.
Your own strings
When you play alone, you can tune your bass relative to itself, which is referred to as relative tuning. For relative tuning, you use one string, usually the low E, as a reference pitch and adjust the other three so they're in tune with it.
When you use relative tuning, you may not be in tune with anyone else's instrument, because the E string you used as a reference for tuning the other strings may not be a perfectly tuned E. But if you're not playing with anyone else, who cares?
A tuning fork
The tuning fork gives you one reference pitch only. It corresponds to the sound of the open A string, the second-thickest string (although several octaves higher). The tuning fork gives you an excellent way to tune your bass, provided you follow these steps:
Strike the tuning fork against a hard surface and place the handle of it (without touching the two prongs) between your teeth.
You can now hear the note A resonating in your head. Note: You may not want to share your tuning fork (other than with that special someone), and you may want to keep it reasonably clean; otherwise tuning with the tuning fork could leave a bad taste in your mouth.
Tune your A string to the A of the tuning fork.
Tune the other strings to the A string.