Tracks from artists like Sheryl Crow available online
Apple's online music venture has got off to a strong start since it was launched on Monday.
About 275,000 tracks were sold in its first 18 hours, according to the US music magazine Billboard.
Apple's music service offers songs from artists such as U2, Eminem and Sheryl Crow for download at 99 cents (62p) per track, with no subscription fee.
The initial success of Apple's offering contrasts with the mixed fortunes of other commercial music services run by the major record labels.
Apple's entry into the online music market appears to have paid off.
Through its iTunes Music Store, it is offering more than 200,000 songs from music giants BMG, EMI, Sony Music Entertainment, Universal and Warner.
Apple boss Steve Jobs launched the new service
In contrast to other legal music services, there is no subscription fee.
Instead people can download tracks for 99 cents each and copy them on to as many as three computers.
The music can also be burned on as many CDs as you want.
Apple's straightforward approach seems to have paid off, with about 275,000 tracks sold in the first few hours after launch.
The figures are more surprising given that the music service is limited to Mac users in the US, though the company plans to launch a Windows version by the end of the year.
Cost of music
The rise of online file-sharing services like the now defunct Napster has created new challenges for the record industry.
The major labels have been trying to develop their own digital music services such as Pressplay and MusicNet.
These have been slow to take off. In comparison to Apple, most charge a monthly subscription fee and limit what you can do with a track once you have downloaded it.
But some are still sceptical whether offering songs for 99 cents will persuade people to abandon popular file-sharing services like Kazaa, where they can download music for free.