Taylor swift has had many different hairstyles over her music career, I thought I'd do a bit of research into her main styles:
Taylor was more frequently seen with curly hair in her early career. Apparently her hair is naturally curly but she often emphases her natural curls by using hair curlers. She has had hairstyles ranging from very tight ringlets to loose waves. The curls give her a romantic look especially combined with her blonde hair, fairytale looks and girly fashion. The album covers of all her first album (taylor swift until speak now) feature her with curly hair. When she has curly hair she wears her hair either parted in the centre or to the side sometimes with side sweeping bangs.
Taylor looks strikingly different when she has straight hair especially when she was younger like in parts of her music video "our song". In her video "You Belong with me" her hair is straight but with a messy texture, however she is frequently seen with very smooth sleek straight hair. Her new album Red features her with straight hair unlike the previous albums. Recently she got a full blunt front fringe suited to straight hair and this has become her current look for 2012/2013. Personally I prefer her with straight hair and it helps tone down the girly romantic look she had in previous years.
Taylor is also known for the fancy updos that she wears at awards ceremonies and also in some of her music videos. She often uses braids and waves keeping the curly texture of her hair. She also usually leaves hair out at the front to frame her face which again keeps the romantic image. Her video to "love story" demonstrates this well. Some of her updos take inspiration from the 20s such as in this photo where she has a 20s style wavy bob and general vintage hollywood glamour such as here. However since getting her front fringe her up styles have been a lot more sleeker such as seen here. There are many many tutorial on youtube of how to do taylor swift hairdos, for example her 2013 grammy's updo.
In music videos taylor has been seen wearing slightly different styles than she usually wears. For example in "You belong with me" she plays the part of the 'villian' herself by wearing a brown wig. She looks very different with brown hair but she can pull it off i think. In her music video for "I knew you were trouble" she also has slightly different hair. This time her hair is dirty blonde in colour with the ends dyed a fading pink and cut short to look slightly punk. I'm assuming its also a wig. Still I like how its edgier than her usual look.