There is a debate that a vocalist is not the same thing as a singer, and it can be difficult to understand those differences. Depending on who you ask will depend on the answer you receive. Female and male vocalists are sometimes thought to be backup singers, performance artists or just plain singers. Any vocalist can be a singer, but not all singers can be vocalists.
Read Music
A female vocalist should be able to read sheets of music, though they do not play an instrument. Many times, singers need to know exactly when to start singing, which can be found when a certain note is played or a series of notes. They will likely need to memorize the music and their singing parts so they can do a performance without having notes with them. This also allows them to practice by themselves, even if there is no recorded music or band to help them know when to come in.
Stage Presence
Most vocalists will have a stage presence, and it will be different for each vocalist. Some will have a certain style, wear certain clothing or act a certain way while on stage. While they will likely be nervous before a big show, they will be able to harness that nervousness to be better than they ever thought they could be.
Most will be able to vary their pitch, pronunciations and feeling based on the song, which will change the piece slightly and make each one different and profound.
Lead Singer
Many believe a vocalist is the lead singer in a band or singing group. In musical genres, such as jazz, a vocalist is the only one singing and may not be used for each song. Any professional singer can be considered a vocalist, depending on who you ask. Therefore, determine what your definition is first and then seek out a female vocalist that can handle what you need.
Bring Depth to Music
Music is a form of art that is different from every other art form because it can change with each passing day or hour. A vocalist will be able to put emotion into their words and lyrics so that people feel moved or angry, causing a more emotional stirring for the crowd. They typically love to perform and use their stage time to project a specific feeling. Many believe that a vocalist is an actress that sings, because they are performing something while on stage that cannot be found anywhere else.