Billboard, which has plenty of music industry sources, still hears a deal is happening, but also reports hearing various issues have slowed down the process, with the video being one of them.
Others include: 1) The sheer size of the deal - Apple is used to buying smaller companies. 2) Concerns about how Dr. Dre and Jimmy Iovine will fit; Apple reportedly isn't sure if they should be consultants or full-time employees. 3) Negotiating a price for the Beats Music streaming service, which is only partly owned by Beats Electronics.
The magazine also states (citing a source "in and around" the talks) Apple was "nowhere near ready" to have media reports of the deal break when they did.
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