Before we dive into the single-string guitar tabs, let's take a brief look at the chords and melody of "Ek Hasina Thi." The song is written in the key of C major and features a simple, yet catchy melody. The chords used in the song are:

e|---5---7---8---7---5---3---| e|---0---3---5---7---5---3---|

Verse: C - G - Am - F Chorus: F - G - C - Am

The melody, sung by Udit Narayan and Alisha Chinai, features a beautiful blend of stepwise motion and leaps, creating a sense of longing and yearning.

Here are the single-string guitar tabs for "Ek Hasina Thi" on the high E string (thinnest string):