B. When you have two notes that are on different lines, the interval is either 3rd, 5th, 7th or 9th. If the lines are next to each other, (from line 1 to line 2, from line 2 to line 3, etc.), the interval is a third. If the notes skip one lines (from line 1 to line 3, from line 2 to line 4, etc.), the interval is a fifth.
C. When you have two notes that are on different spaces, the interval is also 3rd, 5th, 7th, etc. This is because they skip a line note. If the spaces are next to each other (from space 1 to space 2, from space 2 to space 3), the interval is a 3rd. If the notes skip one space (from space 1 to space 3, from space 2 to space 4), the interval is a fifth.
D. When you have two notes where one is a space note and the other one is a line note or vice versa, then the interval is 2nd, 4th, 6th or 8th.
E. When you have two notes where one note is a space note (1st space) and the other note is a line note right above the space note (2nd line), then it is a 2nd. When you have two notes where one note is a space note (1st space), and the other note is a line note (3rd line, skip the 2nd line), it's a 4th.
Take a look at the following interval exercises and determine whether you can tell the interval within 2 seconds.
Develop the habit of reading sheet music by reading intervals.
