When writing a persuasive speech, it is a good idea to try to incorporate the three main elements of persuasion, namely, ethos, pathos, and logos.
To include ethos, you need to present your argument as credible and convincing. You can do this by providing credible and authoritative sources that support your argument. For example, if you were trying to persuade somebody to buy a pair of trainers, you might cite an endorsement from a famous, successful athlete. If you were trying to persuade somebody to take global warming more seriously, you might cite a report from climate scientists.
To include pathos you need to appeal on an emotional level to your audience. You need, for example, to make them happy or excited to take the action. Another way to develop pathos is to make the audience agree with the position that you are recommending from an emotional standpoint. To connect with your audience on an emotional level, you might use emotional language. You might make them feel like they have a role to play in the positive change with which you are persuading them to agree.
Finally, to include logos, you need to prove to your audience that your argument is logically sound. You can do this by proving the links between the changes that you are advocating for and the positive outcomes that you claim stem from those changes. If an audience is convinced that the action you are recommending will lead to positive changes, and can clearly understands exactly how the action will lead to the changes, then they will likely be persuaded to support your position.
As for the attention-grabbing opening, there are several ways in which you might achieve this. You could, for example, start with an interesting question. In this instance, for your chosen topic, your question might be: how do you feel after listening to your favorite piece of music? A broad, relatable question like this will immediately engage your audience. Alternatively, you could start with a surprising fact or statistic, which perhaps contradicts a common misconception that your audience might have. Or you could start with a personal anecdote about your own experiences with music. These are just a few ideas. I have provided below a link to a brief video which offers a few more ideas. Good luck with your speech!