Apple says that while the iTunes Store's revenue in 2014 is bigger than the previous year's number, the company noted that music sales have fallen over the past 12 months.

In a report filed Monday at the Securities and Exchange Commission, Apple said iTunes Store generated a total of $10.2 billion in net sales during 2014 compared to $9.3 billion during 2013.

Like Us on Facebook

"Growth in net sales from the iTunes Store was driven by increases in revenue from app sales reflecting continued growth in the installed base of iOS devices and the expanded offerings of iOS Apps and related in-App purchases," the report said.

The company added that the number was offset by a decrease in digital music sales.

Although Apple did not divulge just how much the digital music sales have decreased, the Wall Street Journal cited "people familiar with the matter" Friday who said that the sales of digital music at the iTunes Store have dropped  to just 13 or 14 percent since the year started. The publication then reasoned that the sales have dipped due to the growing competition from cheap music, such as the $10-per-month unlimited subscription plans and free videos.

Apple also acknowledged the effect of such rival services in its regulatory filing.

"The Company's digital content services have faced significant competition from other companies promoting their own digital music and content products and services, including those offering free peer-to-peer music and video services," Apple wrote.

Rather than buying the albums, consumers have increasingly turned to listening to the tracks for free or cheaply through services such as Spotify and Pandora.

Apple is not alone in the troubles caused by free or inexpensive music streaming. The mobile app Shazam has also experienced such difficulties, as the app only recorded the number of titles bought by customers decrease from 1 million in March of last year, to only 400,000 in the previous month.

TagsiTunes Music sales, Music sales, Digital music sales, Securities and Exchange Commission, iTunes, Spotify, Pandora