In the 19th century, the most revered pieces of music often featured four movements that collectively lasted as long as over two hours; in the 20th century, popular music tracks averaged about three-and-a-half minutes.

For the 21st century, it would seem, the excitement surrounds tracks that last ten seconds or less, as RealNetworks' acquisition of ringtone provider WiderThan yesterday, and British telecom services firm 2ergo's acquisition today of US-based Proteus, brings to four the number of major linkups in the ringtone space just this week.

WiderThan's target market thus far has been its native South Korea, but its plan has been to expand its global presence, with a market strategy that appears more family-friendly than some of its counterparts. In the United States, WiderThan has some "on-deck" deals already worked out with carriers, including one with Verizon Wireless' VCAST service, although that deal is non-exclusive.

RealNetworks was quick to boast yesterday that WiderThan's revenues for the first half of this year grew 39 percent over the year-ago period to $61.9 million. By comparison, Jamba reportedly earned $74 million for then-parent VeriSign in that company's fiscal second quarter alone, although that number is way down from previous earnings, and Jamba's Jamster service is supposed to be the better performer.

In Q4 2005, VeriSign disappointed the street by reporting Jamba revenues of $94 million, when analysts had expected them to top $100 million.

Meanwhile, you may want to get a piece of paper to make sense of this next part:

2ergo, which owns a portfolio of companies in the mobile telecom space, including US-based ringtone provider Zobmob, purchased US-based Proteus. On paper, Proteus is another telecom holdings company, but whose major deals of late have been with media companies for the rights to produce ringtones based on popular franchises. For instance, ringtones using the voice of South American soccer stars, is all the rage on that continent.

Proteus is owned by the US division of Norweigian telecom carrier Telitas, which lately has found itself in the ringtone business. Telitas is itself owned by a Japanese telecom services company called For-Side, which in 2004 acquired ringtone provider Zingy from an American entrepreneur. In August 2005, For-Side merged Zingy with another US ringtone provider, Vindigo.

So did 2ergo acquire Proteus' ringtone portals along with its ringtone contracts? It doesn't appear so, as Zingy was not mentioned in 2ergo's press release today. Instead, 2ergo may have effectively unplugged Proteus from Zingy in order to plug it into Zobmob (as strange as that sentence sounds).

All this polysyllabic news comes as mobile telecom analyst Telephia projects that the total worldwide audience for mobile content of all types -- ringtones included -- grew at an annual rate of 45 percent in the second quarter of this year.