This decision is worth making before you commission charts, because the charts are written for the section you have and rewriting them later isn't a small job.

Three horns

Trumpet, tenor and trombone, or some near variant. A three-horn section can play the melody in unison and voice a straightforward triad, which covers most soul and Motown material well. It's the smallest section that still sounds like a section rather than a soloist with company. Book of forty charts: $1,800 for a wedding band, $1,440 for everything else.

Four horns

The biggest single jump in what's possible. Four parts let you voice a full seventh chord, which is what most of the horn writing people have in their heads. If you're choosing between three and four and the budget allows four, take four. $2,400, or $1,920 for a non-wedding band.

Five horns

Now you have doubling options and can leave a player out of a voicing without the chord collapsing. Five is where a section starts to sound wide rather than merely full, and where the section becomes more interesting to write for. $3,000, or $2,400.

Six horns

A small big-band sound, real weight behind a chorus, and enough parts that a missing player is survivable on the night. It's also six fees every gig, forever, which is the part bands underweight when they're excited about the sound. $3,600, or $2,880.

Where the diminishing returns are

Going from three to four changes what your band can play. Going from five to six changes how big it sounds. That's a real difference, and it's why I'd push most working bands to four before I would push anyone to six.

The other constraint is rooms. A six-horn section in a small venue is loud in a way that can't be fixed by asking politely, and the bands that carry six mostly play rooms that can take it.

Before you commission

Count the players who reliably show up, not the players on the group chat. Charts written for five and played by three sound like a mistake. Charts written for three and played by three sound like a band. What a horn chart is covers what you get, and the full rates are on the pricing page.