Apple

Tim Cook, chief executive officer at Apple Inc., speaks during the keynote of the World Wide Developers Conference (WWDC) in San Francisco, California, U.S., on Monday, June 10, 2013. Apple Inc. introduced a new music-streaming service along with sweeping changes to the software powering iPhones and iPads, seeking to blunt the advance of Google Inc.s Android mobile operating system.

David Paul Morris/Bloomberg via Getty Images

Shares of Pandora Media and RealNetworks each tumbled 4 percent on Monday after Apple announced its Apple Music digital service will launch June 30 for $9.99 a month.

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Some investors fear the soon-to-launch Apple product could slow the growth of rival services like Pandora and Rhapsody, a joint venture partially owned by RealNetworks. Others that could be affected include Spotify, iHeartRadio and Tidal.

Pandora, which offers a $4.99 per-month premium service but also features free accounts, is considered the leader in the industry with 200 million registered users. Its shares dropped 70 cents on Monday to $17.69, giving the company a $3.8 billion market capitalization.

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Rhapsody has a $4.99 and a $9.99 service and it allows multiple users on a single account. The joint venture boasts 2 million paying subscribers. Shares of RealNetworks fell 25 cents to $6.82, giving the pioneering new-media company that first made a name for itself with its RealPlayer software a market cap of $246.2 million.

Apple, of course is a major player in digital music already via its iTunes store and it acquired a service called Beats Music when it purchased Beats Electronics, best-known for its headphone business, for $3 billion last year. Apple Music will integrate Beats One, a global Internet radio channel with  DJ's that allows users to skip tracks.

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Shares of Apple rose 1 percent on Monday to $127.80, giving the company a market cap of $736.3 billion.

According to PricewaterhouseCoopers, digital music streaming will be a $1.8 billion industry in the U.S by 2018, at which time it will pass digital music downloads, which will be a $1.7 billion business.

This article was originally published by The Hollywood Reporter.