Common Chiffchaff

His song is jerky, very rhythmic, tsip tsap. Hold the call with one hand, blow a first time. Then, while cling the window of the largest of the metal tubes with one finger of the other hand, blow dryly a second time. Renew the sequence several times. The two sounds must follow one another, tsip tsap.
Depending on the birds, start again up to seven or more times.
For the simple cry, plug the ends of the two metal tubes and blow a single small blow, tsiuu.