Hi Charley,
It's a Mistle Thrush. They are bigger than Song Thrushes but that doesn't help a lot if you only see one on it's own so 2 identification points 1. Song Thrushes look very 'leggy', they are the chorus girls of the bird world; 2. Song Thrushes have streaks rather than spots; here's one in the garden recently, note the streaky underside with the spots overlapping and running together. Compare with the slightly more spaced spots on your bird and on Pie's.
For sound, Song Thrushes repeat a phrase two or three times, sometimes more and sound more melodious, they also have a wider repertoire than the Mistle, although that varies with age, younger birds are much more limited and repetitive. By that I mean that they will come back to a phrase and repeat it yet again.
'The time has come' the Song Thrush said 'For me to find a mate.
I'll start to sing my love-song and leave the rest to fate.
I know that I repeat each phrase, and that's not like other birds;
It's not that I'm not sure of the tune, I can't remember the words!
But the season is getting on a bit and if someone doesn't come soon,
I'm afraid that I'll remember the words and then forget the tune'
Bill.