Your mother has a baby grand piano.

你妈妈有一台小型三角钢琴。

And a baby grand piano.

和一个婴儿钢琴。

Have you ever listened to Val play his baby grand?

你听见过瓦尔演奏他的小型钢琴吗？

Have you bever listened to Val play his baby grand?

你听见过瓦尔演奏他的小型钢琴吗？

Stretch to change length from baby grand to concert grand size.

可拉伸以改变其长度，从小型钢琴变为平台大钢琴。