The 17-year-old Cromwell College pupil impressed judges at the SmokefreeRockquest regional finals in Wanaka on Saturday and took second place - as well as the Smokefree women's musicianship award.
It was the second time Miss Rankin had been to the Rockquest regional final, after winning the lyrics award with another singer in 2006.
She has progressed to the next stage with southern regional winners, the Slur-Tones, from Wanaka.
Finalists must record about 15 minutes of their original music on DVD for judges to view, from which six finalists will be chosen for the national finals in Christchurch on September 5.
Miss Rankin said she expected competition to be tough, but hoped she would stand out.
She started playing guitar four years ago so she had something to put her lyrics to, and in the past year had taught herself to play the harmonica.
"Writing lyrics is like having a diary. It's not like I write a song every day, but sometimes you bottle everything up and then it comes out in a song," she said.
She prefers acoustic guitar over her electric model, and says her inspiration comes from a variety of genres.
She spent last year on exchange in Pennsylvania, in the United States, where her host family was heavily involved in music.
"My host dad was in a band and he helped me record two of my songs on to singles," she said.
"America was somewhere I always wanted to go and it definitely influenced my music."
During her time overseas, she opened a charity rock concert and played live at a few other venues.
Her own family is also musical, with two uncles who play guitar, including her paternal uncle Willie Rankin, of Wanaka.
Miss Rankin plans to study massage therapy at polytechnic next year, but would like to pursue music further.
This year is her last at secondary school and she will will play the character Miss Kitty in the college production of How The West Was Warped.
