From Monday to Wednesday in San Francisco, TechCrunch’s latest Disrupt Start-up Battlefield competition will showcase entrepreneurs from 30 start-ups vying for a $50,000 prize by making six-minute-long quick pitches to a rotating panel of venture capitalists, tech influencers, angel investors and Silicon Valley players. Monday featured three sessions of Start-up Battlefield, titled Disrupting Traditional Markets, Moving the Web Forward and Entertain Us; here are the start-ups presented in session one, Disrupting Traditional Markets.

Tonara ^[1] aims to become the “Kindle for sheet music” via (somewhat ironically) an inexpensive iPhone app that transforms the way musicians practice. The impressive tech underlying the app can follow along with the music being played via tone recognition, automatically load the next page at the appropriate time, filter out ambient noise and even provide feedback about the performance.

Farmigo ^[2] wants to collapse the traditional supply chain for farm- and artisan-sourced produce and products by removing both the warehouse and supermarket, bringing customers and suppliers together via group-buying mechanics at convenient locations–a workplace, say, or gym or school–chosen by the relevant geographic communities. Farmigo, which takes a transaction fee per purchase, looks to be a more convenient (and scalable) type of community-supported agriculture project that also adds value to farmers and suppliers via tools such as web-based tracking and analytics.

HouseFix ^[3] is a sort of CarFax for the home improvement space, using history reports, social recommendations and vendor accountability to help those with home projects find the right contractors, as well as help those same contractors expand both their client base and online presence. Currently free, the service provides context for homeowners, who can search through vendors who have worked on similar projects at a similar price level within a specific geographic area, while contractors can build up a HouseFix score based on reliability, customer satisfaction, the ability to work within budget and other metrics.

Openbucks ^[4] wants to tap into what the company says is a 97 million-strong market of consumers in the U.S. alone (including a large number of teens) that are shut out of simple e-commerce transactions because they don’t have a credit card, debit card, or bank account. Openbucks users can use regular gift cards purchased from six major offline retail partners, including Subway, CVS, Sports Authority and Hess, and deposit the full purchase price of the gift card into accounts for use with various partners in the online gaming and digital goods spaces.

CakeHealth ^[5] wants to reduce the clutter, redundancy, opacity and stress of insurance documentation, medical bills and employee benefit information with an streamlined and easy-to-use web-based site. Like the Mint financial management site for the insurance and health care space, CakeHealth compiles key data from your insurance information (how much you’ve paid out-of-pocket this year versus what insurance has covered), medical bills (what has been paid, what is redundant with separate insurance paperwork) and employee benefit information, then creates a user-friendly display and navigation experience. It sets reminders for prescription pick-ups or to alert you that a covered check-up is about to expire, and even allows you to take pictures of various documents, from which the site will pull, organize and display relevant information.

Read more about Tonara ^[1].

Read more about Farmigo ^[2].

Read more about Housefix ^[3].

Read more about Openbucks ^[4].

Read more about CakeHealth ^[5].

Watch today’s live stream of TechCrunch Disrupt ^[6].