The notes of the strings on a 4-string bass guitar, are: E, A, D, and G. For a 5-string bass, the string notes are: B, E, A, D, and G. For a 6-string bass, the string notes are: B, E, A, D, G, and C. The bass is tuned in fourths for standard tuning. Similar to learning your octaves, learning your fourth intervals can be a very helpful pattern for learning what the notes are across strings.