Your orchestra or band conductor is handing out parts for a new piece, and there are first and second parts for the flutes. First flute usually plays a higher, more technical and exposed part. Second flute tends to be lower in register and less complex. Let's use Beethoven's Symphony No. 7 in A Major, Op. 92 as an example (click image to enlarge):
The first flute part, on the left, plays twice as much and has lots of 16th notes. Second flute, on the right, spends a great deal of time resting or playing sustained notes.
So first flute's the more important one, right?
Yes, in younger ensembles the less skilled flutists tend to play the second part, because the notes are usually a little easier. But once you move beyond learning notes and fingerings, each part reveals its own challenges and helps you to develop a different set of skills.
First flute requires confidence, especially if you are the section leader, which is also known as the principal flute. Your part is usually exposed and technically difficult, and sometimes includes a solo. The ideal first flutist will be responsible enough to practice their technically difficult part on their own time so that rehearsal can run smoothly. First flute is about being a role model.
First flute also requires the ability to be a chamber musician no matter how large your ensemble is. Even if you're in a group of 100 members, the principal flute needs to be aware of what their fellow principals (oboe, clarinet, violin, etc.) are doing. Are you all using the same articulation? Are you aware of when you have the same melody and are you lining up well when that happens?
In a similar vein, the first flute needs to be aware enough to know when other instruments have the same melody as them but at a different point in the music. For example, in the Beethoven symphony seen above, the melody that happens in the first flute starting 11 measures before rehearsal letter B also occurs at different points in the violin and oboe parts. It happens first in the oboe, and is then handed off to the violin before the flutes play it. The first flutes should be listening intently while this is happening to make sure that their own instance of the melody matches the articulation and expression established by the oboe and violin. This sensitivity, while necessary in a competent first flute, is a skill we also associate with the ideal second flutist.
Second flute requires adaptability. You have to become a chameleon who can match any tuning, tone color, or vibrato that the first flute throws your way even if it's not what you yourself would choose to do. Second flute is about matching your sound to what you hear.
Let's use the Beethoven symphony that we looked at earlier as an example of why adaptability matters. 12 measures after rehearsal letter A, the first and second flutes are playing mostly the same notes. This is usually referred to as playing in unison; you could also say that the second flute is doubling the first flute part. Regardless of the term you prefer to use, the second flute needs to be vigilant to follow the first flute's lead on tuning when playing passages like this one. Shaky intonation is most obvious when two instruments are playing the same pitch.
It's also important to realize that while the principal flute is responsible for the overall tuning of the flutes in an ensemble, it's the second flute section's responsibility not to drag the tuning down if they're playing something in the extreme low register. Be aware of the flute's tendency to go flat when playing low notes and compensate accordingly.
In addition to having a tendency to go flat, low notes are hard to hear on the flute, so the ideal second flutist will have a strong, clear tone in the low register. If you usually play first flute and are assigned second flute for a piece, take it as a compliment to your low sound.
At its core, the role of second flute is about being humble and flexible enough to follow someone else's lead.
If you want to be a well-rounded musician and collaborator, don't just focus on solos, fast fingers and racking up the most practice hours. Add the skills of the second flute to your toolbox and allow them to enrich your solo and ensemble playing experiences.