According to an example aspect of the present invention, there is provided a wind instrument apparatus, comprising: an attachment element configured to attach the apparatus to a wind instrument, a spring structure attached to or comprised by the attachment element, and a support bar. The support bar is partially insertable into the elastic structure and the apparatus comprises a fastening mechanism configured to selectively fasten the support bar in relation to the elastic structure, so that the flexibility of the attachment element is adjustable in relation to the support bar.