I've been trying to learn how to play guitar by ear for a while now,
(I can play guitar, I just can't listen to a song and play it back)
I'm not working on any solos or clean stuff, just the rhythm guitar riffs, so far I've got Judas Priest's British Steel and most of Metallica's Kill em All learned totally by ear, I was wondering if anyone had any suggestions for what albums to do next.
Bonded by Blood and Welcome to Hell seem like natural next steps but after that I'll be a little lost.

Witchfinder General: Death Penalty

Bonded by Blood is a good idea and I'd suggest the first Slayer album.

While it ain't a bad idea, bear in mind that you're just making things harder for yourself; having some knowledge (even if pretty basic) of musical theory will help you a lot -think of it of adding more tools at your disposal.

That aside, the first Candlemass' albums and Black Sabbath are easy and fun to play (most doom in general is, really).

How is this making things harder? The OP, as far as I can tell, didn't say anything about lacking basic knowledge of musical theory. I myself know basic musical theory, and have for years, but I still can't play by ear for shit. So, I'll be watching this thread if anything else gets posted...

Well, I got the vibe that he was learning to play just by using the ear and not giving attention to the theorical side of the music from what he posted. Sorry if I misunderstood you, OP.

Don't know what to tell you about your problem though, I've been playing bass for a bit over two years by now, and I've found that the solid-er my bases on the paper are, the easier it's learn stuff by ear (say, it's infinitely easier to realize in situ that a song makes a II-VII-IV-VI-V-I cadence that trying to memorize each note or tab without relation to the other in order to play them back). I've actually gotten to the point where I rarely bother learning any song by memory, since it's easier just to pick up the bass, listen a bit to the song to get a feel of the harmonic structure, and then start playing around a bit until I get the patterns. Of course, this works to an extent, there's some stuff of a complexity above of my understanding which I can't take on yet, but I know I'll get there on time.

This'll sound funny, but try an old black metal album. Since a lot of the notes are obscure it'll be harder to listen for them. I think that helped me pick up intervals faster.

I use a mix of theory and ear playing when learning new songs. Sometimes, if you can catch the general key/scale being used just by listening, you'll very quickly and easily pick out the rest of the notes/chords that the song is using. Your ear can then be the confirmation that it's correct. This requires both hearing and theory but it's a real quick way. Most session musicians who HAVE to learn a lot of songs in a short amount of time do something like this. Or they just open up the songbook and sight-read everything but that skill is way beyond me.

I agree with the above though. Pick something that isn't super hi-fi.

Does anyone have recommendations for those of us who are far behind being able to learn Kill 'em All by ear? I can only do extremely basic things. I have a modest but tolerable theoretical background -- I just have really undeveloped ears, I guess. Ideas for working on this? Spending time at my keyboard playing and singing notes in a variety of ways is helping so far, but I wondered if anyone might have other suggestions.

2 ways.

1: Just learn it the 'wrong' way. As in, play what you think it is and be done with it. This makes for a more original take on the song anyway, its YOUR way of playing it. Just makes sure it sounds good to you and play it with confidence so it sounds convincing.

2: Use the tab first(be sure to find an accurate one) and then put the dots together. Meaning, see the relationship between the notes on paper and how they sound. Once you get a better idea of what a note sounds like and where it is on the fretboard, you'll be well on your way to being able to learn songs by ear.

There isn't really a shortcut. Just keep at it til you get better. Personally I used a mix of 1 and 2, but mostly 1 because I hate reading tabs. I am terribly slow at it and can never get it accurately anyway.

Actually, singing and playing the notes you sing is my best advice, that's how I learned. When you come by a difficult passage on the song you want to play, you can then stop, sing the notes and find them easier on your instrument. And of course, practice every day... A couple of years ago I did all guitars on all Arcturus' albums, one song per evening. Everything since then has been a piece of cake.

I would not recommend using tabs at all, simply because correct and readable tabs are so hard to find (from my experience at least). If you want notations, rather go to the library and get yourself a book of rock-classics, or perhaps find pirated material online.

There is not one single tab on the internet that is 100% correct. I'm certain of that. And even if the tabs are somewhat right, you can bet your last Ernie Ball the fingerings and positions are off.

Honestly mate, all it is is time and a huge amount of practice. When I started playing guitar, I played for a few months and when I got a bit better, I tried to learn Toxic Holocaust songs by ear, then some Venom and other thrash stuff. The best thing you can do is pick songs that are not too crazy, such as albums like South of Heaven, Black Sabbath s/t, King Diamond (forget the solos, they are godlike) and Mercyful Fate.

It will come, just have patience and don't be hard on yourself.

Oof, yeah. I've played and written music on and off for like ten years, but I've just spent very little time playing other people's songs, and no time learning anything by ear. Consequently, I have a really atrophied aspect of my musicianship... So I've begun working on singing exercises with my new keyboard to develop my ears, and then I'll turn to attempting to transcribe some simple-ish songs. It's intimidating as fuck, but it has become clear to me that it's an essential skill, so I better get to it.

I say start your training by playing modern pop songs. The crappier the better, Katy Perry, James Blunt and the likes.
Then you will start recognising harmonic patterns, since all pop songs use very similar chord progressions. After a short while you'll start recognising the patterns, and you won't even have to pick up your instrument to check. You know it is a I-vi-IV-V (C Am F G*), or vi-IV-I-V (Am F C G*) progression as soon as you hear it.
Once you know these basic forms, it will be real easy to pick up when there are deviations to these patterns and you'll be able to move on to more and more complex harmonies.

*assuming we are in the key of C

The problem with starting out with thrash (or death for that matter) is that it doesn't have a basis in harmonic structures, but rather riffs, which mostly are made up by chromatic and/or "unharmonic" sequences. Kill 'em All is an exception though, the song Motorbreath for example is just a slight variation on the previously mentioned pop patterns.

Right, I see. That makes sense. I do have secondary interests in writing more "traditionally" structured non-metal songs anyway, so it would be valuable to familiarize myself with these patterns.

My biggest problem, as far as I know, is not with recognizing individual notes -- chromatic or otherwise -- but rather isolating notes when a lot is going on. At the keyboard, I can play a note, sing it, and then sing the fifth. But if I just play a note and the fifth, it's actually quite hard for me to hear the root and the fifth so that I can sing either one while the chord rings out. Weird!

Thanks for the continued help, and sorry to the OP if I've hijacked the thread...

Bumping this ancient thread for good reason other than it being my first post on here (yay me).

Any advice for learning tracks with awful quality? Maybe putting the track in my DAW and boosting/cutting certain frequencies?

Hear the track in one ear, hear your amp in the other. If there's a lot of noise, then cutting it down with an EQ helps - I just do it in my media player.

...I guess that would help. But if the song is so lo-fi that it's impossible to tell if you're playing it wrong, does it matter much?

anything by amon amarth is pretty easy to learn by ear