I'm splitting this into a separate post to not spoil the people going to the episode post for links with song titles. They can be pretty spoilery.
In case that wasn't enough, WARNING: SPOILERS BELOW.
Anyway, go get all the songs in HD!
Hearth's Warming Eve Is Here Once Again (HD Update)
Say Goodbye to the Holiday' Song (HQ Update)
The Seeds of the Past (Applejack Song) (HQ Update)
Pinkie's Present (HD Update)
Luna's Future (HQ Update)
Hearth's Warming Eve Is Here Once Again (Reprise) (HQ Update)