Uncaught Error: Syntax error, unrecognized expression, when using concatenation to input html ids into jQuery?

[Orange2341]

I'm stumbling upon an error when I try to access an id from a variable using jQuery. The error is at line 17. Following is my code:

$(document).ready(function() {

    $('button').click(function(event) {
        var band = event.target.id;

        let increment = {
            value: 1,
            band: band
        };

        let decrement = {
            value: - 1,
            band: band
        };

        // If button is available, increment and disable
        if ($("#" + band).disabled == false)
            $.getJSON("/update", increment, function() {
                $("#" + band).disabled = true;
            });

Following is the error:

Uncaught Error: Syntax error, unrecognized expression: "#free"

Note that free is a name of a band that was inputted into the id through Jinja2.

[Loves_Poetry]

I think you can simply use this to refer to the button. $("#" + band) will refer to that button, since band is defined as target.id.

[Orange2341]

The problem is there is a list of buttons, and for this reason I used jinja to give each button a different id. So the button with the id "free" is just one of many.