Not completely different. You can still play all types of music on an electric guitar. Electric guitars were invented so that they could be louder through amplification.
Early electric guitars were just acoustic guitars with a magnetic pickup stuck on.
As the body was an echo chamber and amplifier itself, making it louder became problematic as the amped noise would travel back to the guitar, bounce around the body and back through the pickup to create a screeching "feedback loop".
As they evolved, it became obvious that solid body guitars (no cavity & no soundhole) gave great feedback-free results at high volume. (around late 1930s) They really suit loud music.
The slimmed down electric guitar body suits many people who don’t like lurching over a jumbo sized acoustic guitar.
They are made to be amplified, so strings can be thinner as they don’t need to be acoustically loud. Thinner strings are easier to push down onto the fretboard. Lots of people like that.
Thinner strings reduce the need for a thick neck to hold back the pressure of 6 steel strings.
Thin necks can be a joy to play, especially for people with smaller hands.
The difference between an electric and an acoustic is also about the sound. Without a large cavity in the body, and a body made of thin woods to vibrate in resonance with the thicker strings, the character of the electric sound is very different.
There are also electric guitars in a group we could call "electric-acoustic" which have hollow bodies but generally electric pick-ups. The hollow body can cause the guitar to feedback at relatively low volume so this type of guitar is obviously not suited to loud playing. A good one might be loud enough you don't really need to plug in to enjoy playing it.
Many aren't particularly good at sounding like a typical acoustic with not much body for a sound.
When plugged in they feed back at higher volume so are not always good at being electric.
Why are they still popular? A lot of great music has been made with them and people like the tone produced. Many just look great too with arched tops and curved backs.
Jazz players particularly like them but they can be versatile guitars with the main limit being volume level and use of heavy distortion which tends to create feedback problems too.
My wish is to have the best authentic acoustic sound with the easy to play advantages of a thin electric style body, thin neck and thin strings.
No-one has created such an instrument but hybrid acoustic/electric guitars with acoustic pick-ups, chambered bodies, thin necks and several different pick-up types (Like Godin Multiac) are extremely close to providing a versatile acoustic guitar that is also a good electric guitar. They are not a cheap budget line thing but the direction of this product is nearly perfect and about as good as it could get.
Acoustic guitars have a wider dynamic range and fuller overall tone.That is influenced by having chambers to amplify the sound and additionally the generally thicker strings.
Acoustic guitars with pick-ups usually use a piezo pickup which behaves more like a microphone.
Some have a piezo and a microphone as well so that the sound is as real acoustic as possible.
New technology has come up with the "modelling guitar" and "modeled guitar sound libraries".
Companies like "Line 6" and "Roland" have used modeled guitar sounds in the Roland guitar synthesizers, and the Line 6 Variax guitar.
Roland require an outboard box that carries the sound libraries of famous guitar sounds and you play your guitar but the sound is that from the library. It is very effective.
Line 6 went a different route and built the sound library and extra switching into the guitar itself.
It is surprisingly effective too.
There are plenty of examples of recorded music where an acoustic guitar sound or electric sound has been used that was chosen from sampled recordings (modeled guitar sounds), not a genuine played by hand, live acoustic or electric guitar sound. It would be difficult for most people to recognize this difference, especially in the context of other musical backgrounds.
But for me, they are not always effective substitutes.
I love acoustic guitar and the genuine subtleties of an instrument played by hand, but I need an electric guitar as well for it’s part of a guitarist’s complete toolbox..
Electric guitar’s better at:
- Speedy styles
- Effortless chording
- Easy bending
- Teaming up with effectors for almost limitless sounds: distortion, flanging, reverb, delay,chorus,octave etc.
- Avoiding feedback, particularly at high volumes & using dirty sounds.
- Live music home recording for the singer-player. When you don’t want your guitar sound mixed up with your vocal, the almost inaudible sound of an unamped electric won’t creep into your mic. Monitor through headphones.
Here’s some things you should know about your electric guitar:
DIFFERENT STYLE REQUIRED
The thin strings on most electric guitars are much closer to the fret-board than on most acoustic guitars. If you have been playing acoustic guitar, you may need to adjust your style so that you are not heavy-handed with the electric. If you are, the strings slap, buzz and vibrate against the frets.
Leads are from around cheap & nasty $6 to $30 for an average quality. Special quality with gold tips, better insulation, hot switch guitar cables with magnetic attachment (that is don't turn down your amp, unplug and switch guitar without pops and noise) etc. can cost hundreds. You must avoid treading on them. When removing them from sockets pull from the head of the lead - never the cable. I have a whole box of useless leads so you can't be too careful with them. There is a correct way to roll them up so there are no kinks, knots or twisted cable. They last much longer if you are careful.
When playing, hook the lead under the guitar strap so there is no weight on the connection points. You’ll have less trouble with failed connections and are less likely to rip the connections out accidentally.
Not all leads are the same. Guitar cable is typically unbalanced (mono) cable which is the source of a lot of noise. The cable has 2 wires in it.
Speaker cable is different though sometimes appears with the same connectors. It has to carry high power signals not the tiny signals produced by electric guitars.
Some cable that looks like guitar cable is called TRS cable and it has 3 wires. 2 of the wires carry the same signal but out of phase. When the signals get to their destination, any difference in the signals is understood to be noise and is eliminated. TRS cables are used for microphones and studio monitor speakers but won't work to reduce noise for an electric guitar because the guitar doesn't have a balanced signal output.
There are mechanical elements to the connection points that can come lose or break. Tighten loose nuts or the fitting may well drop out. This happens pretty regularly for the plug in point on your guitar.
Electrical components can also corrode. Any rust or corrosion in a circuit can stop it functioning cleanly and also add unwanted noise.
There are sprays to clean circuits. If you live in humid and salty environments you'll will need to spend more time maintaining the instrument.
Different pick-ups types are available. Single coil pick-ups were an early invention and though loved can be quite noisy with the long coils of wire in a pick up acting like a radio aerial.
Humbucker pick-ups were invented to reduce noise. Gibson are one of the main companies using this style of pick-up.
A later variation is the active pick-up. It is rare in electric guitars but the pickup has a battery pre-amplifier which reduces the need for long coils of wire in the pick-up so they are relatively noise free.
An electric guitar has to have something to make it louder.
Guitar amps are specialized in this field and there are too many choices. A major distinction that bothers or attracts some people is that "old school" style uses valves in the circuit. The plus is a warm vintage sound. The negative is valves need to be replaced here and there.
Some offer a valve preamp and can potentially give you anything else any other modern amp has.
Many modern amps do quite well without valves, using only modern circuits. Many of these have huge multi-fx options which can be stored and arranged as favourites compared to the original old traditional amps which have few options.
These days there are easy alternatives such as plugging straight into the band's mixer, usually first going through a foot pedal so the guitarist gets a whole range of different sounds with the press of a pedal and a built in tuner.
Most pedal boards also have headphone sockets for quiet private practice.
Some double up to become a recording interface to the computer.
Too many choices but for a live performance you always need some kind of amp with speakers.