I’ve googled the heck out of this and can’t find a straight simple answer, although I can find contradictory answers. I’d appreciate it if someone who knows with certainty would explain to me exactly what each term means, including vocal range, and clarify if they are or are not EXACTLY the same. Thank you.
For bonus points, throw countertenor in there too. EXACTLY the same range as alto but sung by a male, or slightly different?
Unlike instruments, the human voice is not as rigid in range or performance. People differ. Wikipedia’s entry on Contralto should answer your question. Is there a reason why you need to be so precise?
From another angle: “Alto” is typically used to indicate a voice part in choral singing, whereas “contralto” typically references a solo voice. I’ve never seen a choir with a “contralto” section, nor have I ever seen a (female) singer described as an “operatic alto”. A solo voice lower than a soprano is a mezzo-soprano or a contralto, but not an alto.
This can be confusing because the other standard choral voice parts, “soprano”, “tenor”, and “bass”, are used for solo voice types as well. But “alto” is not.
Yes, there are male altos, and sometimes they’re considered interchangeable with countertenors, and sometimes they’re differentiated as baritone falsettists versus very high head-voice tenors, but AFAICT the distinction is pretty fluid.
Curiosity. If there are two different words, I’d like to know if they exact synonyms or if there is a distinction.
This is the most helpful (and most concise) answer I’ve seen.
An excellent point, and the essence of why the question arose in the first place.
It’s not quite as simple as “choral part” vs. “voice type,” however. While they are often treated as the same range, alto as a choral part refers to the part above the tenor part. But the contralto voice type will often sing in the tenor range, rather than above it. It makes sense: the prefix “contra” tends to mean “lower than” in music terms, e.g. contrabass instruments being lower than bass instruments.
A key reason for this is that the vocal types are divided into 3, while the choral parts are most often split into 2 or 4. There are the sopranos, mezzo-sopranos (often just mezzos), and the contraltos. But choral parts are usually soprano and alto, with each sometimes subdivided, giving Soprano 1, Soprano 2, Alto 1, Alto 2. Even when I do see three-part female choral pieces, they are usually SSA, i.e. 2 soprano parts and one alto part. (I honestly didn’t even know mezzos existed until I got to college.)
So you wind up with contralto voices that sing Alto parts (orAlto 2), but also sometimes some mezzo-soprano voices (or Alto 1). And you’ll have both mezzos and sopranos that sing Soprano 2 parts, or just the lower Soprano parts.
Something similar happens with male parts, as well. The baritone can usually cover the classical choral bass range. But a the bass vocalist usually has an extension below this, at least for a few notes. And the baritone can often cover the lower parts of the tenor range, albeit with a heavier production. So you still have the same mix with two/four choral parts, but 3 vocal types. The main difference is just that the baritone has only been acknowledged as a separate part more recently, and is still often just considered a subtype of bass. A baritone may start out singing lighter bass parts and then transition to singing heavier tenor parts. But their voice range didn’t change so much as they changed focus, and better developed their upper range.
SATB hasn’t always even meant men and women. The choirs were originally all men, with the sopranos being unchanged male voices, either using children or the castrati, whose name probably tells you what that means. Thus it’s not surprising that such doesn’t map perfectly to the vocal classification types of men and women.
So, while the “vocal part vs. vocalist” is a good first order approximation for alto vs. contralto, I’d say the bigger difference is between how the voices are divided. The contralto vocalist can usually sing lower than most alto parts. It’s not uncommon, especially in smaller or less advanced choirs, for a contralto to cover tenor parts. (My grandmother did this a lot in church choirs.)
Thanks everyone for your replies. The question has been answered to my satisfaction (for now, anyways ;)).
“contr” obviously 
Brian
So is a woman who sings the same range as a male tenor a contralto, then?
I knew about the distinction between sopranos and mezzos when I was still in high school, because my main squeeze was a soprano and the big busty girl I lusted after (on the side) was a mezzo, and they sang in a trio. The alto was also cute, but I wasn’t really interested in her.
I was in a barbershop quartet with my good friend Roger the Bass Player, and I wanted to sing bass, but he insisted on singing it himself, so I took baritone. When we went to a contest, singing the Yale Men’s Chorus version of “High Barbary,” we got the top grade, with the judges adding “Great, GREAT baritone solo!”
In your FACE, Roger the Bass Player!
Q: What’s the difference between a countertenor and a contralto?
A:
The countertenor doesn’t have hair on his back.
Yes, if you use the classical system. Though, to be more specific, she’d be called a contralto profundo if she can cover the entire tenor range in a full, strong voice.
More commonly, their range is slightly higher, and can only mostly cover the tenor range. Such women would be known as dramatic contraltos. The common range is from the E below middle C to the E an octave above middle C. The classical tenor range is the C below middle C to the C above it. So there would be a difference of four notes.
But such ranges are always an average.
When I see things like Soprano 1 and Soprano 2 in sheet music, I assume that they’re singing in the same range, just different parts, and if there’s any substantive difference between them, it’s just that the 1 is more skilled than the 2. By comparison with instrumental music, the First Trumpets are playing the same horn as the Second Trumpets. Not so?
Generally speaking in choral music it’s vocal range, followed by skill. Soprano 2 may not always be lower than Soprano 1 in absolute terms (e.g. voice crossing or counterpoint of some sort) but Soprano 2s almost never get some of the EXTREMELY high notes that are rare even for Soprano 1 (say above an Ab above the staff).
This isn’t necessarily skill, there are some extremely skilled sopranos who are essentially diehard soprano 2s due to vocal type, unlike with wind instruments where parts are often divided by skill/importance. A lot of Soprano 1s will also trade off being 1 and 2 during long concerts so their voices can rest.
Note that Soprano 1 is a good 90% of the time the melody, but that’s just because it’s easiest for the top part of the harmonic structure to have the melody. I’ve seen every voice have the melody, including weird parts like “Alto 3” and such. This is especially common in non-SATB voicings like SSSAAA which will put the melody wherever they damn well please for the next 5 measures.
stifles laugh
clears throat
“That was mean!”
I learned as a kid in music class that a contralto was a female tenor, and a countertenor was a male soprano.
There aren’t usually enough of either in a choir for them to have their own separate part.