Name That Tune

[Wander]

Sorry, but this is all going to be a big vague.
Whilst out today, I heard a bird call that I just can't identify.
It's not the first time I've heard it.
Unfortunately I don't have a recording of the call, so will have to transcribe it as best I can.

It was a strong call (not a song!). Sorry to use the word 'tweet' but that's very much what it sounded like:

Tweet Tweet, Tweet Tweet, Tweet Tweet.

Strong, moderate tempo.
I thought it might be part of a Song Thrush call, it had that strength and regularity to it, but never went on to other notes as one might expect from a Song Thrush.
Even more unfortunately, I never caught sight of the bird.
Part of me still keeps thinking Song Thrush, but I've listened through various Song Thrush calls and it's not there.
Any suggestions?

 

[TLM]

Try xenocanto, a lot of weird calls there.

 

[Broch]

To be honest it could be a number of things - best go onto a site and listen to some more likely candidates.

However, a constant tweet, tweet - I would put money on a great tit.

 

[Wander]

It was a Nuthatch:

 

[Broch]

Or that

 

[FerlasDave]

It was a Nuthatch:

Fantastic! My favourite of the native songbirds