Originally Posted by Whoswho1:
“what was reused? series 7 music would not fit with tone of 8.”
Off the top of my head, though there's probably more...
The closing scene of
Death in Heaven, when The Doctor and Clara say goodbye before she walks off down the high street. A whole track lifted from
The Time of the Doctor track 'Beginning of the End'.
A track from
Asylum of the Daleks titled 'The Terrible Truth' was used near the ends of both
Into the Dalek and
Death in Heaven - twice in the latter!
The fallout between Clara and The Doctor at the end of
Kill the Moon reused the track 'I Might Change My Mind', originally used near the end of
The Bells of Saint John.
The track 'Somewhere to Hide' from
The Day of the Doctor was reused partially in
Flatline.
A track from
Robot of Sherwood that's been dubbed 'May Our Story Never End' is an original piece, but takes inspiration from both Series 6's 'The Wedding of River Song' and The Special's 'Four Knocks' track.
When Clara reunites with The Doctor at the end of
Deep Breath, they reuse music from 'The Leaf' which originally came from
The Rings of Akhaten. The scene continues into the phone call with the Eleventh Doctor, which in turn (appropriately) reuses music from
The Time of the Doctor, namely the track 'Song for Four'.
That's without new takes on Clara's theme which were heard, as well as another reworking of the Cybermen theme in the finale. And then on top of that Series 8 reused a lot of its own themes several times over (i.e. 'Fear is a Superpower' was used again in a hefty number of episodes) which is fine, though again reduces the amount of new material for a new soundtrack. Maybe they're opting for longer, fewer tracks rather than the shorter cues we've seen creep in?