Favorite intervals!

and on what instrument have you accomplished that if you are so familiar with this interval?

If folks have suggestions, I'd love to be able to look up some example of these obscure intervals that people are mentioning. When you just play the interval on the piano, there is no difference between an augmented 2nd and a minor 3rd. Is there somewhere that I can hear it in context that suddenly makes it clearly an aug 2 instead of a min 3? Or is it dependent upon the scale only? Just curious.

and on what instrument have you accomplished that if you are so familiar with this interval?

In approximation, I use both of them very often on the piano, but if you have a good tuner then it's not so hard to reproduce them on the guitar or other instruments which can be retuned easily (remember if n is the fundamental's frequency then the second harmonic will have a frequency of 2n, the third one of 3n, then 4n, 5n etc.). There are also many audio examples on the internet, plus you can always hear some spectral music to get a feel of the overtone series. Also, I believe you can also use MIDI tuning, but I am not familiar with it...

and on what instrument have you accomplished that if you are so familiar with this interval?

Any brass instrument would make you easily familiar with that interval, but to a lesser degree, most instruments offer rather natural access to it (such as strings by use of natural harmonics). It appears already rather low in the harmonic series, so it's not usually too difficult to get.

If folks have suggestions, I'd love to be able to look up some example of these obscure intervals that people are mentioning. When you just play the interval on the piano, there is no difference between an augmented 2nd and a minor 3rd. Is there somewhere that I can hear it in context that suddenly makes it clearly an aug 2 instead of a min 3? Or is it dependent upon the scale only? Just curious.

It is merely dependent on harmonical/melodical context. There's no single, clearly-defined frequency ratio for either interval that would distinguish them fundamentally. The exact "size" of an augmented 2nd or a minor 3rd would depend entirely on the music it is used in and on performative practice. So when people say they "like the sound of an augmented 2nd", they aren't truly speaking of -sound- that is distinct from a minor third, but of a certain implied context (particularly, the aug 2nd implies an interval that tends towards an outward resolution rather than being a consonance).

I hate to ask, but what is an acute fifth and a neutral second?

The "other" option can be put up, but it generally changes all the votes, so I don't think I can do that.... but I can try

IF IT HAPPENS I AM VERY SORRY!!!

Neutral second = 3/4 steps wide, it is used in arabic music quite frequentley.

Acute fifth = perfect fifth (3/2 ratio) plus a syntonic comma (adding up to a total of 243/160) A close approximation is found in 5-TET, which is used in gamelan music.

And since not everyone here might be aware of what a syntonic comma is:

A syntonic comma is the "difference" between a just major third as you'd find it between the fourth and fifth harmonic, and the major third you'd get by stacking four perfect fifths on top of each other. This, and the other most known comma (the pythagorean comma, which is the difference between 12 stacked fifths and a just multiple octave), are some of the major "problems" that many tuning systems in our history sought to "solve", which resulted in various temperaments.