Shazam, a provider of mobile music discovery applications, has surpassed 50 million users worldwide, with 15 million more users added since February 2009. 

The London-based company also announced strategic investment from Kleiner Perkins Caufield and Byers, or “KPCB,” who had also assisted leading digital consumer businesses such as Google (News - Alert) and Amazon.

The music discovery service from Shazam is live in more than 150 countries. Company officials said that more people around the world are accessing the service every day and are using it with increased frequency discovering and acquiring new music and sharing them with friends via their mobile phones.

Shazam recently announced the availability of its music discovery application for Windows phones via the newly launched Windows Marketplace for Mobile.

Shazam will be offering a free version as well as a full-featured version which users can access for a one-time fee.

Initially, the Shazam applications on Windows Marketplace for Mobile will be available in English in more than 30 markets around the world. Shazam expects to roll out multi-language versions in the coming weeks, officials said.

“Shazam is profitable and experiencing sustained acceleration in its growth rate,” Andrew Fisher, CEO of Shazam, said. “We are delighted to be partnering with KPCB, who join our existing investors Acacia Capital and DN Capital and will help us execute against the significant market opportunity ahead.”

According to Matt Murphy who led the investment for Kleiner Perkins and manages the iFund, “Shazam’s leadership in the massive mobile entertainment and discovery category positions them to be at the forefront as it evolves.”

The mobile music discovery technology allows users to record music by simply holding a mobile device towards a song as it is playing. With the launch of iPhone (News - Alert) 3G in the summer 2008, the company has seen significant growth. Shazam’s application has been downloaded more than 10 million times on the iPhone App Store. 

Shazam’s application was also ranked as the highest downloaded applications on BlackBerry App World, Nokia’s Ovi Store and Google’s Android (News - Alert) Market. In all cases, Shazam is consistently rated among the most popular applications on each respective platform. 

KPCB is in the early days of the mobile application phenomenon. The investment is being made from its iFund and will enable the company to continue to expand accessibility of the service around the world by continuing to develop applications for additional mobile platforms and in multiple languages.