(Reuters) - Amazon.com Inc said it was working on a music subscription service that would cost about $5 a month and would only work on its Echo hardware, Recode reported, citing sources. Amazon would like to launch the services in September, but has not finalized deals with major music labels and publishers, Recode reported. The Recode report said one sticking point, sources say, is whether Amazon will sell the cheaper service for $4 or $5 a month.