A Great Tit calls

I was sitting outside (in quite a breeze) and all I could hear was the repeated notes of bird song - two notes repeated three times, over and over again. It took me a long time to locate the Great Tit high in the branches of the tree, but eventually I found him -  there he was singing his heart out. He was high up and there wasn't much light, but I had to record this. A lovely sign of Spring.