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The interval between, say, C4 and D4 is a major 2nd.

What is the interval between B#3 and C4?

Is it still a 2nd?

For lack of a better term would it be something like a minor minor 2nd?

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up vote 9 down vote accepted

You have:

  • B# - C: Diminished 2nd (same as B-Cb)
  • B - C: Minor 2nd
  • B - C#: Major 2nd (same as Bb - C)
  • Bb -C#: Augmented 2nd

If I'm not mistaken, there are also double diminished and double augmented intervals, like Bb - Cx but rarely used

Generally the interval qualities are: Diminished, Minor, Major, Augmented or Diminished, Perfect, Augmented.

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Thank you, I recognize this now. – Jason Feb 25 at 6:53
Worth mentioning that on a keyboard instrument, this is recognized as a unison, but there is a difference on other instruments such as string instruments (where a sharp is played differently as a flat, e.g. in F#-Gb diminished 2nd). – Pierre Arlaud Feb 25 at 10:18
@PierreArlaud F#-Gb would be a unison both in a piano and a guitar. What is exactly your point? – Shevliaskovic Feb 25 at 10:20
@Shevliaskovic my understanding is that technically, F#-Gb is an enharmonic interval and both notes are separated by a comma. On a violin you would make a slight difference (Bb should not be played exactly the same as a A#), which is impossible on a piano. – Pierre Arlaud Feb 25 at 10:39
@Shevliaskovic to avoid an extended discussion, I can thankfully redirect you to this answer This would in theory be a problem if one violin played an A# and another one a Bb, but having both notes written at the same time on the sheet would seem very experimental to me. The point was: a diminished second is not exactly a unison as there is a very thin difference between a sharp and a flat or between a chromatic and a diatonic tone. – Pierre Arlaud Feb 25 at 10:49

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