How can the OCC change the chart?

The above has been true seemingly for rock/guitar acts since the advent of downloading, as it appears that fans of those genres prefer not just paid-for purchasing, but largely in the physical format. Hence since the late '00s we've witnessed a gradual takover of more urban, produced genres which for some reason seem to do well on download, and now also seem to benefit significantly from their popularity on streaming. I can only surmise that this is mostly to do with demographics, in that guitar and rock-based acts are more likely to be beloved of more 'mature' fans - and I don't just mean vintage artists such as ELO but even more current people like Biffy Clyro - and those consumers generally tend to stick to CD or vinyl, with limited take-up on download, but hardly any on streaming.

Another genre that will markedly lose out due to the rapid rise in streaming over sales is the teen pop/boy and girl groups -acts like 5 Seconds Of Summer, The Vamps et al seem to do better on paid-for than rented. Perhaps they're not regularly included in these 'most played' playlists of Spotify's (not being a Spotify user I wouldn't know but it wouldn't surprise me). This will presumably make it harder for the latest talent show crop to harvest an instant chart-topper, even at Christmas, when they must now compete against other acts who have legions of fans choosing the streaming platform, and whose tracks will be much more mature in that sector having been made available some weeks or even months ahead. It seems that brand of young pop is now being eaten away by the likes of Justin Bieber and Drake who do nothing special on sales but are constantly streamed.

The only brand I can see still outperforming on sales to the extent that it manages to overhaul the latest high-streamed offerings clogging up the chart are occasional charity releases, which of course traditionally do very nicely on CD, but then fall away swiftly, having limited appeal to downloaders, and even less to streamers.

Personally, whilst I don't mind the fading fortunes of some of the above, I don't feel they're being replaced by anything especially worthy, and it does rather imply that the current brand of over-processed, studio-led, urben-inflected basic pop productions will continue to dominate the Top 100 to the detriment, and possible exclusion, of other genres which sometimes deserve better. Albums compensate for this lack of variety to a degree, but with sales looking so weak in that market, it doesn't feel like much of a trade-off for artists who just can't get enough leverage on streaming or download to score big hit singles, regardless of how much support they might receive from major radio and TV stations.