Music Concert DVD’s # song plays # – why no lyrics?

First off, if there are any fans reading, this is not an attack on the band Take That. I am a fan. Why else would I own some of their DVDs?  I am just using them as an example to illustrate something that I find puzzling about music concert DVDs. More often than not there are no subtitles at all. Sometimes when there are subtitles it is only for the spoken dialogue. For example the DVD feature – behind the scenes of Take That’s Beautiful World tour is very helpfully subtitled. Here’s an example:

Take That - Beautiful World DVD

Behind the scenes, documentary, commentary, interviews are subtitled.

For that I am grateful. But why isn’t the main feature – the concert on the DVD subtitled? Take That’s The Circus Tour DVD– no subtitles Is this down to lyrics and copyright? And if that is the case, why then if the same songs and therefore the same lyrics air on TV those lyrics are then subtitled. In this case the TV channels are doing a better job than the DVD distributors. If its down to copyright does that mean technically TV channels shouldn’t subtitle lyrics? That’s absurd as well. The inconsistency is confusing. I’ve read somewhere (I wish I could remember where) that concert DVD’s are sometimes listed as ‘E’ Exempt from requiring subtitles. Why?! I would like concerts on DVD to be fully subtitled to include song lyrics. On my Twitter account I asked if anyone knows if the DVD box sets of Glee are subtitled and include the lyrics. I never got an answer from anyone which is a shame as I’d of liked to have included the info in this post. For those that don’t know Glee is a popular US musical drama series. When broadcast on UK TV of course the songs and lyrics are subtitled – it would be impossible to follow without. I don’t see anything different about music concert DVDs. The only music concert DVD I own that does include subtitled lyrics along with dialogue is Michael Jackson’s This Is It:

The entire main feature is subtitled, including the song lyrics.

This was released as a movie so perhaps is categorised differently as a movie DVD which isn’t “exempt”, but again, why different rules/approaches for different DVDs? Can anyone shed any light on this?