Spectrogram of song (and other sounds) from a bluethroat (= Mastersingers, Blue bubbles movie). Sv: Blåhake. Storådörren, Sweden, June 9 (?) 2012. Beside the bluethroat's many imitations and other more or less peculiar sounds (including the bubbling starting at 1'9"), you can hear a cuckoo, (very faintly) a willow warbler and a reed bunting, and finally (more close) some mosquitos.
Telinga Pro 5 parabole with stereo DAT mic, recorded on the camera tape. The "noise" from the nearby stream has here been reduced somewhat through a gentle (7,5 dB) filtering. Sonogram from Izotope RX, screen capture with Debut v. 1.83.