Seconds can be major, minor, augmented or diminished. Below you can see that the number of half steps determines the quality of a second.

Major second, 1 whole step or 2 half steps:

Minor second, 1 half steps:

Augmented second, 3 half steps:

Identifying seconds

Seconds are probably the easiest intervals to identify. Yet, it is essential to master the identification of seconds to be able to identify other intervals.

To identify the quality of a second we must know:

• the number of half steps contained in each type of seconds
• the order of musical notes (C, C#-Db, D, etc.). We must remember that between all natural notes, with the exception of E-F and B-C, there is a distance of one whole step.

With this in mind, we can count the number of half steps in a second:

Another way of identifying seconds

If both notes are natural, we don't have to count the number of half steps if we remember that only the seconds E-F and B-C are half steps. If there are accidentals, we can use the following method:

• Make all notes natural and determine the quality.
• Add the accidentals and see how the interval is affected.

Example: G#-A#:

• Make all notes natural. G-A is a major 2^nd (only E-F and B-C are minor).
• Add a sharp to G. The interval is now smaller, it becomes a minor 2^nd Add a sharp to A.
• The interval is now larger, it becomes a major 2^nd.

Another example: C#-D double sharp:

• Make all notes natural. C-D is a major 2^nd (only E-F and B-C are minor).
• Add a sharp to C. The interval is now smaller, it becomes a minor 2nd.
• Add a sharp to D. The interval is now larger, it becomes a major 2^nd.
• Add a second sharp to D. The interval is now even larger, it becomes an augmented 2^nd.

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