So before Black Sabbath existed, most rock bands played in E Standard tuning. This is the tuning that guitars were generally designed to be played with. Here's what it looks like:
As most people reading this probably know already, Tony Iommi had an accident early on and the tips of his fingers were sliced off. So his fingers used to bleed. This is generally regarded as the reason Black Sabbath started loosening the strings and tuning way down. Although lowering 1 or 2 strings was pretty common when playing blues/slide guitar, it was not common to lower ALL the strings down equally in the early 70s, not even in the hardest rock music. Initially Sabbath went down a half step to Eb/D# standard (Eb and D# are the same note btw) and here's what that tuning looks like:
Later, they went even lower to D standard and finally the C# standard:
That pretty much covers all the tunings they used in the 70s. So which tunings were used on which albums? Below is some more detail on that. Some of you reading this may be beginners and some of you may be shredders. Since I have no idea who will be reading this, I'll assume you are a beginner so feel free to skip the real basic stuff if it starts sounding obvious...
This album was recorded in standard E. Best way the verify this is to play along to N.I.B. The whole song is in E, and the main riff uses the low E string a lot. So if you play along to the studio version and just strike the low string over and over, you will find it rings perfectly with the tune almost all the way through. It's real easy to solo along to if you start on the 12th fret and play E minor pentatonic. This also happens to be one of the most common scales Tony Iommi uses, so you might as well just learn the bloody 5 note pentatonic scales if you haven't already! Anyhow, the best way to figure out what tuning they are in is to pick a song with a real simple riff (like N.I.B.) that obviously utilizes the lowest open string. Determine what that lowest open string is and you have the tuning. If you hear a note LOWER, than you know you have not found the lowest open note and therefore you need to use a lower note for your tuning to play it accurately. With Sabbath, it's usually the very first note in the song. Some albums deviate, but this first one is very straight forward. Keep in mind, live recordings, even as early as 1970 MAY NOT MATCH THIS TUNING. The band was already tuning lower to Eb within a year of recording this. So when playing along to ANY live Sabbath, you have to remember it may not be in the same tuning it was recorded in!
Black Sabbath tuning: standard E (E B G D A E)
I'm going to reveal a secret here that I haven't seen anywhere else. I'm not sayin I am the first asshole to figure it out, but I'm just saying it doesn't seem to be real common knowledge that this album is NOT in Standard E. However, it is SUPPOSED to be! Let me explain...if you grabbed a guitar as I suggested and tuned it using a tuner you aughta be right in tune with N.I.B. or anything else on the first album. But if you play along to the song War Pigs or PARANOID(both of which are SUPPOSED to be in E) you will find that it sounds a bit funny. This is because Sabbath actually tuned UP on this album! This had to have been an accident - maybe the recording was sped up or maybe someone in the band was sharp - but the tuning here is a slightly SHARP E standard tuning! But it is NOT so sharp as to be a full half step, so you won't be in tune if you tune UP a full half step. Therefore, you cannot play along to the first and second album without slightly sharpening all your strings for the Paranoid songs! Now you would think that the tuning would correct itself at some point on the album, but the fact is, it's the same on the whole album. So whatever reference point they were using, at least it is consistent! Again, live versions will be lower. In fact, I believe it was the Paranoid tour that they started tuning down to Eb standard. Live recordings from 1970 reflect this as well. Check out "Paris 1970" on youtube for confirmation of this.
Paranoid tuning: (slightly sharp) E B G D A E.
Master of Reality (1971)
I recently heard a rough demo of this album which had some of the songs recorded in standard D. However, they ultimately decided to go down to standard C# for most of it. Best way to verify this is to play along to "Children of the Grave." The first note is C#, and they never play a note lower than this one on the entire album. For further verification, check out the Randy Rhoads tribute album where Randy actually plays the song in the recorded key (C#) while his guitar is actually tuned to E standard (very hard to do - try it!) This is why he plays it higher on the neck and gets away with it! But let's not get side tracked...The exceptions here are "After Forever" and probably "Solitude" which were kept at D standard for some reason. This is probably why they never played "After Forever" live until much more recently. I have not checked whether they went ahead and played it in C# standard or not live, but that would be consistent with Sabbath's history live. They tend to stick with 1 or 2 tunings at the most on a given live performance. It's only a half step, so why bother changing for one song? If you listen to live recordings of Sabbath pretty much from 1971 until 1978 - they play all of their songs in C# standard. Which is why songs like "War Pigs" and "NIB" sound so monstrous from this era. They also did this in 2006 when I saw them at Ozzfest, and I think they went back to this tuning on the last "Farewell tour" as well - presumably so Ozzy could have a bit more of an easy time hitting the notes.
Master of Reality tunings: standard C# (C# F# B E G# C#), standard D (D G C F A D) - on "After Forever" and "Solitude"
Volume 4 (1972)
This album is all in C# standard except the song "Changes" which starts out in the key of B major. However its played on piano, so guitar tuning is not really applicable. To verify tuning, it's best to play along to "Snowblind." First note is C# and the open low string is used throughout the song. Try tuning it even a half step up or down and it's impossible to play along to the CD without sounding all weird. For some reason I thought I encountered a version of "Tomorrow's Dream" in standard D but now I can't find it - which brings me to a quick note - occasionally, someone will upload a song at the WRONG SPEED onto youtube! But for the most part you can count on it. Still, if you need absolute confirmation, ALWAYS use the official CD (not a CDR) or a properly working record player set at the correct RPM! On the Volume 4 tour, they played their entire set in standard c# tuning.
Volume 4 tuning: standard C#
Sabbath Bloody Sabbath (1973)
This entire album seems to continue in C# standard without any deviations. First song on the album is in C#. The main riff is played higher on the neck, but towards the end when Ozzy screams "where can you run to/what more can you do" you'll hear the bottom C# note being palm muted in that signature Tony Iommi style. Another way to check is to play "Spiral Architect." It has lots of open notes and it does not sound right unless you are tuned to C# standard. As I mentioned earlier, the open strings are pretty much the give away to the tuning, as those open strings MUST be tuned to those notes - therefore revealing the tuning at least partially. Also, it helps to pretend you only have 2 fingers (your 1st and 4th) as Tony tended to write parts that were easily played with those 2 fingers. Intro the Spiral Architect is a perfect example. If you are in the right tuning, try using just 2 fingers and you will crack the code to what he's playing. They continue to play their entire set in C# standard on the Sabbath Bloody Sabbath tour - there is great footage of them playing around that time if you look up "cal jam 1974" on youtube.
This album is also recorded in standard C# tuning. However, I'd like to point out that the band was obviously becoming aware of their overuse of the low C# note, as they get much more creative songwriting wise here. As such, we actually need to use the 5th (F#) string to verify tuning. First note on "Hole in the Sky" is F#. It rings out quite a bit and is the key to playing this song right. Without that open F#, you can still play it but it sounds more stiff and doesn't quite nail the feel. Again - open strings are the key to nailing the tuning. "Thrill of it all " also begins with, and utilizes the open F# as a key to the sound. As a side note - the 5th string ("A" if you are in standard tuning) is very popular in rock and you'll will find all over classic rock radio. So in this sense, the open F#/5th string in C# standard tuning nails a similar guitar rock feel. For some reason electric guitar just wants to rock with the 5th string open! Another good example is "2 Minutes to Midnight" by Iron Maiden and "Mob Rules" also by Sabbath. All rely on that open 5th string but are not all in the same tuning. Anyway, if you really need your low C# confirmation, check out Supernaut where Tony chunks it out a little in between that bluesy 7th chord thingy he does during the verses. Of course, the band continues to play their set entirely in this C# tuning on the Sabotage tour. This would be the last album Sabbath records in the 70s using this tuning. And I believe they never went back to it, except live.
Sabotage tuning: standard C#
Technical Ecstasy (1976)
Clearly getting burned out on the low sludgy doom riffs, Sabbath decides to tune back up to standard E on this album. "Back Street Kids" opens right up with the low E that Metallica would milk the hell out of all through the 80s. "All Moving Parts" utilizes the previously mentioned open 5th string. It was F# in the previous tuning, but now has become the familiar classic rock "A" that bands like Queen, Zeppelin, Deep Purple, and countless others use on many of their popular hits. I'm not sure what Sabbath did for this tour, as the only song I can find from this live is "Dirty Women," which they play on their famous Hammersmith 1978 recording (easy to find on youtube). On that recording, they tune Snowblind UP to E standard - which is why you will find it sounds kinda strange (I personally hate that version!) So if they did tour for Technical Ecstasy, they probable played all the songs in standard E and eliminated most of the C# songs from the set.
Technical Ecstasy tuning: standard E
Never Say Die! (1978)
Never Say Diebegins, again, on the familiar "A" rock chord Tony utilized on the previous album. I don't have to mention it, but I will anyway that this is the same riff Thin Lizzy uses in "the boys are back in town" so there's really no need to further illustrate how the "A" chord (or 5th string) is one of the most ROCKING ones you can play on guitar. The tuning becomes harder to nail on some of the other songs, but if you listen to "Air Dance" Tony plays a chord with the open high E (1st string) at about 44 seconds in. You can't play the chord this way unless you are in standard E. There's some really cool songs played in the key of "F" also, which do not utilize many open notes, and can all be played fairly easily in standard E. I haven't scrutinized this album or Technical as much as the others so I welcome any comments on these, or anything else on this post that you think might be of interest.
Never Say Die! tuning: standard E
Hopefully this was helpful or at least an enjoyable read. Cheers to all Sabbath fans out there!