I have researched famous singers, and it looks like you want to learn how to sing like FDR, the US President? Unfortunately, FDR was not a singer, but he was a music lover, so instead, I will assume that you meant you want to learn how to sing like one of FDR's favorite singers, which was, Billy Murray.

Billy Murray was a popular singer in the early 20th century, and he became known as "The Denver Nightingale." His voice was light and bright, and he was a fantastic singer in both comedic and sentimental songs. To sing like Billy Murray, one needs to possess excellent breath control, the ability to create clear enunciation, and crisp phrasing.

One song that showcases his style and vocal technique is "I'd Rather Be Right." It's a happy and upbeat song that has a clear melody and lyrics. To learn this song, you must first understand how to find your vocal range. Singing Carrots offer a Vocal range test that will help you determine your voice's range. Once you understand your vocal range, you can use the search songs feature to find other songs with similar keys.

To sing "I'd Rather Be Right," you must have excellent breathing technique. Singing Carrots offers a breath support article and a Farinelli Breathing exercise video that can help you improve your breathing and warm-up your vocal cords.

Furthermore, to learn Murray's vocal style and technique, you can try to practice articulation, vibrato, chest voice, and resonating techniques. Articles such as How to find your authentic voice, Voice registers & vocal break, Resonance in singing, and Singing with Vibrato can help you better understand these techniques.

Once you have learned how to use breathing and articulation techniques, try the How to Twang Exercise and the Finger Bite exercise to help develop the vocal agility and dexterity required for this song.

In summary, to learn how to sing like Billy Murray, you need to perfect your breathing techniques, learn to articulate correctly, and know how to use other vocal techniques like chest voice, vibrato, and resonating while practicing. With the right tools, resources, passion, and practice, you can develop a similar vocal style to "The Denver Nightingale."