How can you sustain a long note on electric guitar smoothly?

Question

Sometimes a song calls for a very long sustained note, or a long sustaining chord, such that the length of the note is beyond what you can expect a guitar to naturally sustain, let alone sustain without its quality changing from loss of kinetic energy.

Clearly these are cases where you must revive the note by periodically picking it so that it will maintain its intensity and reach the required ringing time. However, whenever I try to do that, I am painfully aware of when the note is being re-picked. This is because picking interferes with its oscillation, and I feel like that’s noticeable, and because the attack of the pick is audible given enough distortion. And yet, I heard live recordings where a long smooth note was played without these issues.

How do guitar players do that?

Answer 1

Tetsujin gives a good answer (I upvoted), but I feel I can add some additional ideas.

Compression is making quiet sounds louder and loud things quiet, and it is naturally something that amps do when pushed enough. There are techniques common in rock guitar, specifically tapping and harmonics, that could always have been done but weren't common until amplification and compression made it so these could be as loud as normal playing.

Traditional guitar has always been a punchy high-attack low-sustain instrument, but with amplification and compression, you can get these longer notes and chords, but there eventually comes a point where the note fades.

Clearly these are cases where you must revive the note by periodically picking it so that it will maintain its intensity and reach the required ringing time.

There are techniques to handle this. There are technologies to handle this. The first one I can think of is tremolo picking, which you might recall from the meatball scene from Lady and the Tramp. Instead of strumming once and leaning on the sustain, you pick a lot, like on sixteenth notes or so, and let the continual picking be heard as sustain.

Next is the addition of string vibration by feedback. The common way is by standing in front of the amp or monitor and letting the sound move the strings, which get amplified, and so on. The Sustainer and Sustainiac systems use an electromagnet in the neck position to allow it to send the currently-played note back into the strings, not just pick it up. The EBow and similar systems use magnets to just vibrate a string. It's similar to but different from the built-in systems, in that it doesn't know what is being played. This all very much gets you into the infinite sustain thing.

The pedal-steel guitar way is different, in that you use a volume pedal and a loud clean amp. Here, you play the note, drop the volume to where you want it to be, and as the note decays, you add volume back, so it just sounds like the note sustains a long time. This is a bit like doing the same thing compressors do, just with your foot.

Also, the Freeze and other infinite sustain pedals, kinda delay pedals that just play back short samples of a previous note or chord.

However, whenever I try to do that, I am painfully aware of when the note is being re-picked.

There are a few things you can do, but this does skew more ambient and far less rock. The first is to swallow the pick attack. Compression can help a little, but my go-to here is use a volume pedal to hide when I pick. Issue is, now instead of that new click, you get silence.

This is when you use delay and reverb to hide the point in time when the strum or fade happened.

Answer 2

Sheer volume &/or compression.

Live on stage there's enough volume coming back to the guitar string that sympathetic resonances can keep it going.

High-gain amplification also compresses the sound, making this effect more prominent.

In the studio, or at low volumes, you can get something like the same thing by holding the guitar nearer the speaker. You can even do this with a software amp & studio monitors.

You can play to some extent with the frequency component of this using vibrato. A note held steady is likely to increase higher overtones as it sustains - eventually to feedback squeal. Keeping a bit of vibrato going can tame this high-end component. Experts can keep this going infinitely. Selective damping of the other strings is also important.

Check out this 50 second example from one of my favourites, Leslie West [time-stamped to just before it starts] Live in 1971, so let's assume a low-gain amp [classic Marshall] & maybe a fuzz box in those days. Sheer volume & skill is doing the rest. I've always had a guess that towards the end he may be also tapping the body to keep it going. We'll never really know.

Late edit - I found another crowd-pleaser from Gary Moore. He would alway do this long pause followed by the long sustain live. Timestamped to just before the pause, for some audience anticipation…
This is a high gain amp, different beast altogether compared to the more primitive low gain on the Mountain track.

Answer 3

if you watch U2 live you'll see Edge use an EBow to sustain the long notes on With or Without You. He used to use a patented devices called the Infinite sustainer. This was built into a guitar and is visible on the 1987 performance in Paris. ebow at GAK Good discussion here and a write-up on its history and workings here

I recall a comment from Edge in about 1987 tha tyou needed to adapt your technique to mute unwanted strings

Answer 4

You probably need vibrato

Vibrato inherently involves varying the pressure applied to the string to change the pitch. This creates small movements of the string over the fret, and the friction of this movement helps the note sustain by adding energy to the string.

Classical guitar vibrato uses a wrist/arm movement parallel with the guitar neck. This changes the tension on the string without much movement of the string over the fret. You'll still get a little movement over the fret and hence a longer sustain, but not to a large degree.

Rock vibrato though uses bending - it is simply a rapidly repeated micro-bend. You're literally pushing the string across the fret, as with any bend, and the friction of this on the fret puts energy into the string like you're using a bow on a violin. With the high gain of an electric guitar, you can use this to make a note sustain almost indefinitely.

Plus feedback

With the guitar close to the amp, you get a feedback loop in the same way as a mic close to a speaker. If you damp the other strings, any undamped strings will tend to ring on their own. Sometimes this can be unwanted, but if you give it a frequency to ring at (by picking the note and keeping the vibrato going) then it'll "prefer" to do that. And getting the guitar close to the amp essentially increases the gain to help those small movements create more sound. This is like keeping a swing moving - once it's started, you only need a little extra energy to keep it going.

Answer 5

An example of the increased sustain on an electric guitar using the sympathetic resonance of holding the guitar near to the amp and applying vibrato is shown here. I use this example as it's easy to see and hear the distorted electric guitar and clear what the result is, as described by Tetsujin. Slightly later on towards the end of the track you can see the 'bowed' guitar technique of visually riding the pickup volume knob to hide/mute the picking sound to give an almost 'backwards playing' effect (akin to what Dave Jakoby describes through use of a pedal).

Time stamp 12:15 Guitarist: David Mark Pearce

Answer 6

Maybe not a entirely technically correct answer, but I have had one of these on my pedalboard for years for this exact purpose. It's actually one of my favourite all time pedals :)

https://www.ehx.com/products/freeze/

I often use it for sustaining a chord or note, then (while holding the pedal switch down) play other passages overtop of the still ringing chord. I've also used it for more reliably triggering feedback sustain that the others talk about above.

Answer 7

Chords first, because they're harder. A compressor will make them sustain for longer, but no longer than your guitar is capable of. Distortion has the same problem, but is uglier. Digital repetitions are another option - a delay loop faded into and out of, or a reverb/ambience patch with a long decay.

For single notes, sheer volume is the traditional method. Stand in front of a full stack and turn it up. This will force you to up your guitar game to one that sustains evenly at all frequencies, whether through tweaks or replacement, or get used to dancing around stage trying to get that note to feedback when you need it. It works with smaller amps and lower volume, but less reliably. The chord methods also work.

There are devices - an Ebow vibrates one string at a time with its own signal, using a pickup and an electromagnet, and will sustain for days. A Sustainiac is rather like building six Ebows into your guitar. There was another that clamped to the headstock and vibrated the entire neck with the output from an amp. The re-released Gizmotron uses hurdy-gurdy technology (rotating wheel bows, one for each string).

Answer 8

If it's amplified guitar, you can prolong a sound using compression - either automatically or 'manually' with a volume pedal. Or there's the ebow (and similar ways of continuously exciting a string).

If it's acoustic guitar, vibrato helps a bit. But you might have to admit that guitar is a 'pluck and decay' instrument. Long sustained notes just aren't in its nature.