The song of the Nuthatch is a simple series of repeated notes.
Three examples (Apr, Herts).
The song can be a trill.
Tree Creeper song (Apr, Norfolk)
Another song by the Tree Creeper is a constant repetition of call-like notes, mostly in triplets (5.40am, May, Herts).
The high-pitched song of the Goldcrest (May, Herts).