from typing import List


def compact_chords(line: List[str]) -> List[str]:
    """Compacts a list of letters such that a multi letter chord
    is one element in the list.

    Args:
        line: A list of characters.

    Returns:
        A list of compacted characters.

    Example:
        >>> songsheet.compact_chords(['g', 'm', ' ', 'B']
        ['gm', ' ', 'B']
    """
    ret = []
    el = ''
    for i, char in enumerate(line):
        if i == len(line) - 1:
            el += char
            ret.append(el)
        elif char == ' ':
            ret.append(el)
            ret.append(' ')
            el = ''
        else:
            el += char

    # Hack, why is there an extra empty string.
    return [char for char in ret if char != '']