According to the stratified sampling method, the number of students selected from each group should be proportional to the size of the group. There are 25 sports-talented, 35 art-talented, and 40 music-talented students, making a total of $25 + 35 + 40 = 100$ students.

If we are to select 40 students from the total, the expected number of music-talented students selected would be:
$$\frac{40}{100} \times 40 = \frac{40}{100} \times 40 = \frac{4}{10} \times 40 = \boxed{16} \text{ students}.$$

By establishing a proportional relationship based on the definition of stratified sampling, we can draw conclusions. This problem mainly examines the application of stratified sampling, and establishing a proportional relationship based on the conditions provided is key to solving the problem. It is a relatively basic concept.