Fletcher Henderson is regarded as one of the most significant figures of the big band era. He was instrumental in developing big band jazz, and his influence on jazz remains to this day. Henderson's music had a unique swing to it, and he used a special rhythm section to develop his signature sound.

If you want to learn to sing like Fletcher Henderson, here are a few tips to get you started:

1. First, focus on the swing rhythm. Henderson's music had a notable swing to it, and to achieve this rhythm, you should take long and short notes alternatively. Utilizing vocal techniques like syncopation and dynamics will also help you create the right feel.
2. Second, work on your improvisation techniques. Improvisation is an important part of jazz music, and in Fletcher Henderson's music, it was a vital part of the performance. You should start by practicing simple vocal improvisation exercises like scatting before progressing to more complicated ones.
3. Third, study the vocal styles of the singers that performed with Henderson. Many remarkable vocalists performed with Henderson in big-band jazz, and it is worth studying their vocal style. You can also learn from their staging presence and how they used their voices to express themselves.
4. Last but not least, use Singing Carrots resources to enhance your vocal abilities. Singing Carrots has several resources that can help you improve your voice. You can use the vocal range test to understand your vocal range and compare it to Henderson's; the pitch accuracy test will help you increase your pitch accuracy, while the pitch training will help you develop your voice.

Remember, learning to sing like Fletcher Henderson is a process that takes time and practice. By utilizing the tips and practical resources mentioned above, you will be well on your way to singing big band jazz like a pro.