Concern around US album sales continues to mount, with Billboard revealing on Friday that each of the last five weeks has seen sales of less than 5m units, with the latest – ending 28 July – seeing 4.68m album sales, which is the lowest since Nielsen SoundScan started tracking them in 1991. Cue more cannibalisation chatter, as industry executives try to work out whether streaming music growth is more responsible for slow album sales than an uninspiring release schedule. Actually, the report points to another possible cause: CD sales falling at a faster rate through physical retailers, with a particular emphasis on catalogue albums. Here, too, opinions are split on the likely causes. Catalogue may be more susceptible to cannibalisation from streaming services, yet as one analyst suggests, these are often the albums that would have been shifting in bulk for $5 through retailers – and labels may not have many more classic albums left to discount to that price. As ever, what’s missing from all calculations surrounding this debate is how much money streaming is making music rightsholders in the US, and how much that might be making up for sales declines.