surprised no one commented , its a pretty good tone in my opinion . One thing you could try is to hum the entire song once through if it gets a little tight on the high notes then skip those parts . Just hum through the parts that are comfortable . To do the hum , pronounce the word ' he ' and take note of the position of the tongue . Then hum with that tongue position . the tip of the tongue should rest behind the front of the bottom row of teeth and the tongue should be slightly arched to the roof of the mouth . The jaw should not be tense close nor too open . Use the pronunciation of the ' he ' to get both the optimal mouth opening and tongue position . Sing through the song on the hum , taking note of the feeling of the voice that you feel while humming . Then try to apply that same feeling when you add the words again . You should find if done correctly , the tone should be a little more vibrant and more resonant . Furthermore a hum is a sustained ' m ' sound which will help regulate the flow of air making the voice less breathy . If you are able to translate the feeling of the hum into the words , you should find most of the problems you have listed will start becoming less of an issue especially with regards to resonance and breathiness But really , its a good voice already . just be aware that the hum may not work for you . It tends to work for most people but i have seen it not work for certain people . So if the hum feels uncomfortable then another method would probably be more ideal . But hope this helps either way .