Many years ago, there was a big label called RCA, which was part of the RCA conglomerate, which also owned NBC; one of its biggest competitors was Columbia Records, which was part of the CBS conglomerate, which owned CBS the TV network.

As the industry consolidated in the 1980s and 1990s, RCA eventually got bought by GE, CBS by Sony. The networks and labels were pushed around and passed around like the wimpy kids at a schoolyard basketball game. RCA, home of Elvis, ended up bought by the Bertelsman Group, a German conglomerate.

As the 2000s proceeded and sales of CDs dropped and dropped again, the industry reconsolidated and consolidated some more. BMG and Sony merged their music units, creating Sony BMG; Universal reigned, with about 30 percent of the market, and as for the other former majors, well, everyone is still waiting for Warner and EMI to conclude its laborious courting and merge as well.

That will leave three labels—Universal, Sony, and Warner EMI—dividing some 80 or 85 percent of the industry, with the rest covered by what indies remain.

Anyway, the joint Sony-BMG venture ended today, with Sony buying out Bertelsman at a price that values the combined company at about $1.8 billion, according to the NY Times, and completing RCA’s debauching.

Wall St. Journal story ($) is here.

Why Sony would want the whole label is a mystery. The WSJ says this:

Sony has strategic reasons to double down in the industry.

Mobile-telephone companies, eager to differentiate themselves from competitors, have been striking licensing deals with music companies that could prove lucrative in the future. Sony BMG recently reached such an agreement with Nokia. Sony itself is a partner in Sony Ericsson, a mobile phone venture, and would like in the future to strike deals that benefit more of its divisions.

The acquisition also gives Sony a close relationship with the company that produces American Idol and other television shows that have been critical in creating new music stars.

Sony is also trying to tie together its consumer electronics business with entertainment content, through its PlayStation Network that lets gamers play each other. Its Bravia televisions can also download movies; Sony’s own “Hancock” is to be the first movie offered under that model. Sony has had difficulty launching a music download service. Earlier this year Sony closed down Sony Connect, a would-be iTunes competitor that included a line of portable music players and an online store.

Sony presumably has its reasons, but note that after “mobile phone deals” the rationales get pretty thin pretty fast.  And the back-end savings of the merger have presumably already been realized.