All types of dogs, may it be size or breed, can be easily taught to speak. The method for it to go is to call your dog, show your pup a treat (which never disappoints), and say "Speak".
The dog might probably not understand what you are trying to make him do, and probably would dart on the treat, jumps, and will eye it intently at first. Finally, he will sit down, gets impatient, and then utters a sharp bark which is what you have been waiting for, and for that instant when he does so, reward him with a treat.
Not all dogs love to bark. Just like humans, some are aggressive, and some are just plain shy. For these types of dogs, they can be encouraged to do so by imitating a bark. Chances are, he will reply to it. Reward him, a never-disappointing deed of all time, and then he will learn to bark as soon as he hears the word "speak". Now, after the dogs have been taught to bark once, you can teach him a series of barks. This way, you can make him expect to be rewarded, which encourages him to bark more until you give him a stop signal, which can lead to a full phrase, or whichever you want him to do.
Other than being social beings, dogs are very observant. By the time you signal your pet to stop at the slightest point, your friends won't detect the magic trick, such as subtle movements of hands and feet. A wink or a shift of your gaze, and if you keep up with these tricks, you might be firing up an exciting series of barks that can sound as if your pet is having a conversation. You can address him as if he was a human being to keep his performance appealing, impressive, and very perplexing.
Demonstrating the latter, if you are exhibiting your dog to an audience, and might want him to "speak", you would like to be a bit more creative like asking him a question. That way, you can probably be in a great business to have a "talking dog". That is much better than pestering barks in the neighbourhood.
Now that your dog can "speak", you can now teach him how to "sing". Try making him imitate a series of whines and howls to a certain degree, reaching the pitch, and the style of noise you desire. As your pet learns how to follow you, say "sing" automatically to associate the desired action. With constant practice, a dog can and will learn to develop your turn quite accurately. Do not forget to praise and treat him plentifully for encouragement. Exercise the activity regularly.
By this type of training, you have managed to teach your dog to speak and sing the Sweetie way. Well done!