# Maximum interval between Alto & Tenor, & intervals when writing for SATB

What is the maximum interval permitted between the Alto & Tenor when writing for SATB? I have read it should not be more than a 10th, whereas another source said it should not be more than an 8th. Which one is correct?

Also, when you write for SATB, it is said that you should be writing smoothly, avoiding any large intervals for each of the voices. What should be the maximum interval used in each of the 4 voices? For example, can I have the Tenor moving up a 6th (from `G#` up to `E`, making an interval of a minor 6th)? Or is this interval too large for any voice?

• Wee don't need 'permission' to write anything in music! What we need is any line (SATB) to be singable. If the intervals are too large, some singers wouldn't be happy. But sometimes, the voicing of SATB needs that to happen. Beethoven would write stuff that was too high for some singers. 'If you can't or won't sing it, then don't...' – Tim May 20 '19 at 7:54
• The ascending interval from G# to E is a minor sixth. – phoog May 20 '19 at 15:19
• Oops, yes, you're right @phoog. Forgot the sharp when naming the interval. Thanks, will rectify it. – Grace May 20 '19 at 15:36
• One point worth bringing up, this particular harmonic move at the beginning of an exercise is normally much subtler than this. I going to “vi6” is almost always just a delicate 5–6 motion above the bass (like your soprano), while everything else stays static. It’s a common strategy for connecting a root position I to a root position ii smoothly without parallel fifths. Many theorists don’t even consider the apparent vi6 chord to actually be a full-fledged harmony at all. If this following chord is ii, I suspect this is the implied solution (though yours isn’t wrong per se!) – Pat Muchmore May 21 '19 at 0:53
• @Grace I was referring to the chord after the apparent vi, not shown in your example – Pat Muchmore May 21 '19 at 4:30

Although this is a large leap, it's certainly acceptable in this style. But what's most important is how you resolve this leap.

Typically, a large leap is immediately followed by stepwise motion in the opposite direction; this is sometimes called "gap fill." Thus your tenor line will want to progress from this E down to D and C♯ (or something similar).

What you typically do not want is two consecutive large leaps in the same direction. Moving from this tenor E up another fourth would be considered poor voice leading in every tradition that I can think of.

There is no hard-and-fast rule for what intervals are allowed in each voice. But typically the soprano will be a nice mixture of stepwise (conjunct) motion and leaps (disjunct motion). Often the bass will be a bit leapier, but not always. Sometimes the inner voices jump around, and sometimes they just noodle around two or three pitches for days on end.

As for the distance between the voices themselves, most tend to settle on never having any more than an octave between the soprano/alto and the alto/tenor. With that said, the bass is allowed to be more than an octave away from the tenor.

• Yes, the next chord I've written has the Tenor `E` going down to `C#`. – Grace May 20 '19 at 12:46
• I would emphasize more that the line should be singable and attractive melodically than any rule of thumb about gap fills or no large leaps in the same direction. In C, a line like C B C' (all upward motion) is easier to sing than C B A (gap fill), and arpeggiated triads are always singable. – Ben Crowell May 20 '19 at 21:44

There are no absolute rules.

If you are writing something in a particular style - for an exam for instance - then there may rules for that style, but apart from that case when you are being creative you can do whatever you wish.

Other factors may of course be relevant. It needs to be singable for instance. Other than that do what you want - make it sound how you want it to.

• If you need to write for chorales in the style of Bach, would this (the example I've mentioned) be ok to do? – Grace May 20 '19 at 8:58
• The example you have written looks fine to me. Intervals of a sixth are not normally a problem for singers and that is easily in any decent tenors range. – JimM May 20 '19 at 9:17

The underlying ideal is that every line should be an attractive and singable melody. The harmony should sound like it came naturally out of the melodic lines. The melodic lines should not sound like random strings of notes dictated by the chord changes. Having big leaps, or many leaps, or repeated leaps in the same direction is a problem if it's a symptom of this "random string of notes" syndrome.

If you're not sure whether something is OK, sing it yourself (transposing to fit your own vocal range). Try to sing it from the score without touching the keyboard. If you have trouble singing it, then other people will too. If you think it's awkward or boring to sing, then so will they. If you think an inner part lacks interest when it stands on its own, then tenors and altos will probably agree with you.

Intervals are not hard or easy to sing in and of themselves. It depends on context. For example, there's nothing hard in general about singing an ascending major second -- but it could be very hard if you gave someone a part that was trotting along happily in the key of C and then made a surprising, unprepared step from B to C#.

On the other hand, a leap of a major 7th could be very easy to sing if it was (in C) C B C'. It's a little formula used in cadences, and people will recognize it instantly and be able to sing it fine.

There is a distinction between a vocal style and an instrumental style. For instance, the first Bach cello suite starts with G D B A | B D B D, etc. It's fun to try to sing this, and it can sound nice if you can find the right key to make it work for your voice, but it's fundamentally an instrumental line, not a vocal one. It's natural for the bow to saw back and forth across the strings. It's not natural for the human voice to do this.