There is a handy function called void ags_audio_open_files(AgsAudio*, GSList*, gboolean, gboolean)
taking as parameter filenames as GSList, overwrite_channels and create_channels as boolean. Filenames is a single
linked list of strings, overwrite_channels means use pre-allocated channels and
create_channels to allow instantiate new channels. The boolean parameters can be combined
as you want.