<P> Physical single continued declining in the United States, and many record companies stopped releasing physical singles altogether to concentrate more on album sales . Since its establishment of Billboard Hot 100, singles were not eligible to enter the chart unless they were available to purchase as a physical single . By the late 1990s, several popular mainstream hits never charted on the Hot 100 . No Doubt's 1996 hit "Don't Speak" spent 16 weeks at number one on the Hot 100 Airplay chart, but it never charted on the Billboard Hot 100 . As a result, on December 5, 1998, Billboard changed the rule to allow airplay - only songs onto the chart . Aaliyah's "Try Again" (2000) was the first single ever to reach number one on the Billboard Hot 100 based solely on radio airplay . </P> <P> The internet era introduced music download and streaming as a release format of a single . The demand for music downloads skyrocketed after the launch of Apple's iTunes Store (then called iTunes Music Store) in January 2001 and the creation of portable music and digital audio players such as the iPod . </P> <P> The sales of singles are recorded in record charts in most countries in a Top 40 format . These charts are often published in magazines and numerous television shows and radio programs count down the list . In order to be eligible for inclusion in the charts the single must meet the requirements set by the charting company, usually governing the number of songs and the total playing time of the single . </P> <P> In popular music, the commercial and artistic importance of the single (as compared to the EP or album) has varied over time, technological development, and according to the audience of particular artists and genres . Singles have generally been more important to artists who sell to the youngest purchasers of music (younger teenagers and pre-teens), who tend to have more limited financial resources . Perhaps the golden age of the single was on 45s in the 1950s to early 1960s in the early years of rock music . Starting in the mid-sixties, albums became a greater focus and more important as artists created albums of uniformly high quality and coherent themes, a trend which reached its apex in the development of the concept album . Over the 1990s and early 2000s, the single generally received less and less attention in the United States as albums, which on compact disc had virtually identical production and distribution costs but could be sold at a higher price, became most retailers' primary method of selling music . Singles continued to be produced in the UK and Australia, surviving the transition from compact disc to digital download . </P>

When was the last 45 rpm record made