The thing to keep in mind is that guitar strings, unlike an organ, generate different amounts of harmonic content over the lifespan of the note/strum. Yes, strings also have an amplitude envelope, as bzrkrage and greco appropriately point out. But the harmonic content during each of those four nominal stages of note lifespan (A, D, S, R) is nbot the same. Part of what distinguishes the tone of different categories of guitars is the manner in which they influence the relative harmonic content in response to a picked note. For instance, the floating bridge of a big-box jazz guitar keeps the harmonic content down immediately after picking, but maintains significant fundamental and lower harmonic output pretty high for a bit, resulting in a not-quite-as-bright-but-still-full-sound that many describe as "fat". Many of the studio guys in the 60's who played on soul and funk records (think Eric Gale) would use such guitars. And when later folks would try and emulate the sounds they obtained on records, using this or that pedal, they couldn't do it, largely because they were attempting to do with a Les Paul or Strat what was originally done with a Super 400 or ES-175.
However....
One still has to distinguish between what the guitar itself provides, and the amp and speakers' ability to reproduce it. Then there is the role of cables and mic-ing. In the audio-design world, there is somethng referred to as "slew rate". You'll see chips and occasionally solid-state amplifiers spec'd for slew-rate. In the most basic sense, slew rate reflects the ability of the device/circuit to reproduce large "impulse" voltage swings at higher frequencies. So, if the signal to be passed is not amplified very much or is particularly high (and most audio coming from an electric guitar generally isn't), then you would not hear any difference between a chip spec'd at 0.5V/usec slew rate, and another spec'd at 13v/usec. If the device is being asked to substantially amplify the full bandwidth of a signal, right up to 20khz, AND the reproduction system and your hearing permits one to hear that, you will hear a difference between lower and higher slew rates. It doesn't even have to be all that high. For instance, the legendary Timmy pedal comes with either a 4560 or 4580 dual op-amp chip, both of which have a 5v/usec slew rate. A former forum member here had read somewhere that subbing a 1458 chip improved the tone of the Timmy. He brought his pedal to my home and we tried out about 6-8 different categories/classes of replacement chips that evening and both agreed that the 1458 sounded better. The 1458 has a slew rate of 0.5V/usec, which had the net effect of keeping the top end in check, like sanding down the sharp edges.
Why am I mentioning this? Because amplifiers and speakers differ in how easily and quickly they can respond to high-frequency impulses from the guitar. Big-cone speakers obviously have to be moved from a standing position, and the mass of the voice-coil and cone , and compliance of the cone-surround, can influence how quickly that cone can accelerate and reproduce the pick attack. You frequently see the frequency response of speakers shown, but you never see just how quickly a speaker is spec'd for transitioning from a standing position to some standardized level at various frequencies. So, maybe a 12" speaker can handle the 4-6khz range nicely, but if I was to feed it a 4khz signal, how quickly does it start moving back and forth at 4khz? They never tell you.
Same thing with amplifiers. They must have slew rates too. But the specs provided, and maybe even measured, never tell you. Amp X might be able to reproduce the pick attack of a Tele exquisitely, and Amp Y close but not as well. Some of that will clearly be in the circuitry and tone-shaping, brightness bypass caps, the tonestack, etc. But some will be in the design and what that permits in the way of the amp being able to respond instantly, even at high frequencies, irrespective of what sort of speaker it is dumping the output signal into.
In the case of guitars (which IS the topic of the thread, after all), different sorts of pickups, body woods, bridge placements, and bridge types, will result in an initial pick attack that is either highlighted, or dimmed down to the background. Some folks will even say that the snap on a Telecaster depends on whether the strings are mounted straight, through holes in the rear skirt of the bridge plate, or throgh the ferrules on the back of the guitar, up and over the saddles.